includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if ( !function_exists( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count = 'end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if ( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84
  85 }
  86
  87 if ( !function_exists( 'mb_strrpos' ) ) {
  88         /**
  89          * @codeCoverageIgnore
  90          * @return int
  91          */
  92         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  93                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  94         }
  95 }
  96
  97 // Support for Wietse Venema's taint feature
  98 if ( !function_exists( 'istainted' ) ) {
  99         /**
 100          * @codeCoverageIgnore
 101          * @return int
 102          */
 103         function istainted( $var ) {
 104                 return 0;
 105         }
 106         /** @codeCoverageIgnore */
 107         function taint( $var, $level = 0 ) {}
 108         /** @codeCoverageIgnore */
 109         function untaint( $var, $level = 0 ) {}
 110         define( 'TC_HTML', 1 );
 111         define( 'TC_SHELL', 1 );
 112         define( 'TC_MYSQL', 1 );
 113         define( 'TC_PCRE', 1 );
 114         define( 'TC_SELF', 1 );
 115 }
 116 /// @endcond
 117
 118 /**
 119  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 120  * @param $a array
 121  * @param $b array
 122  * @return array
 123  */
 124 function wfArrayDiff2( $a, $b ) {
 125         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 126 }
 127
 128 /**
 129  * @param $a
 130  * @param $b
 131  * @return int
 132  */
 133 function wfArrayDiff2_cmp( $a, $b ) {
 134         if ( !is_array( $a ) ) {
 135                 return strcmp( $a, $b );
 136         } elseif ( count( $a ) !== count( $b ) ) {
 137                 return count( $a ) < count( $b ) ? -1 : 1;
 138         } else {
 139                 reset( $a );
 140                 reset( $b );
 141                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 142                         $cmp = strcmp( $valueA, $valueB );
 143                         if ( $cmp !== 0 ) {
 144                                 return $cmp;
 145                         }
 146                 }
 147                 return 0;
 148         }
 149 }
 150
 151 /**
 152  * Array lookup
 153  * Returns an array where the values in the first array are replaced by the
 154  * values in the second array with the corresponding keys
 155  *
 156  * @param $a Array
 157  * @param $b Array
 158  * @return array
 159  */
 160 function wfArrayLookup( $a, $b ) {
 161         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 162 }
 163
 164 /**
 165  * Appends to second array if $value differs from that in $default
 166  *
 167  * @param $key String|Int
 168  * @param $value Mixed
 169  * @param $default Mixed
 170  * @param array $changed to alter
 171  * @throws MWException
 172  */
 173 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 174         if ( is_null( $changed ) ) {
 175                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 176         }
 177         if ( $default[$key] !== $value ) {
 178                 $changed[$key] = $value;
 179         }
 180 }
 181
 182 /**
 183  * Backwards array plus for people who haven't bothered to read the PHP manual
 184  * XXX: will not darn your socks for you.
 185  *
 186  * @param $array1 Array
 187  * @param [$array2, [...]] Arrays
 188  * @return Array
 189  */
 190 function wfArrayMerge( $array1/* ... */ ) {
 191         $args = func_get_args();
 192         $args = array_reverse( $args, true );
 193         $out = array();
 194         foreach ( $args as $arg ) {
 195                 $out += $arg;
 196         }
 197         return $out;
 198 }
 199
 200 /**
 201  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 202  * e.g.
 203  *      wfMergeErrorArrays(
 204  *              array( array( 'x' ) ),
 205  *              array( array( 'x', '2' ) ),
 206  *              array( array( 'x' ) ),
 207  *              array( array( 'y' ) )
 208  *      );
 209  * returns:
 210  *              array(
 211  *              array( 'x', '2' ),
 212  *              array( 'x' ),
 213  *              array( 'y' )
 214  *      )
 215  * @param varargs
 216  * @return Array
 217  */
 218 function wfMergeErrorArrays( /*...*/ ) {
 219         $args = func_get_args();
 220         $out = array();
 221         foreach ( $args as $errors ) {
 222                 foreach ( $errors as $params ) {
 223                         # @todo FIXME: Sometimes get nested arrays for $params,
 224                         # which leads to E_NOTICEs
 225                         $spec = implode( "\t", $params );
 226                         $out[$spec] = $params;
 227                 }
 228         }
 229         return array_values( $out );
 230 }
 231
 232 /**
 233  * Insert array into another array after the specified *KEY*
 234  *
 235  * @param array $array The array.
 236  * @param array $insert The array to insert.
 237  * @param $after Mixed: The key to insert after
 238  * @return Array
 239  */
 240 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 241         // Find the offset of the element to insert after.
 242         $keys = array_keys( $array );
 243         $offsetByKey = array_flip( $keys );
 244
 245         $offset = $offsetByKey[$after];
 246
 247         // Insert at the specified offset
 248         $before = array_slice( $array, 0, $offset + 1, true );
 249         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 250
 251         $output = $before + $insert + $after;
 252
 253         return $output;
 254 }
 255
 256 /**
 257  * Recursively converts the parameter (an object) to an array with the same data
 258  *
 259  * @param $objOrArray Object|Array
 260  * @param $recursive Bool
 261  * @return Array
 262  */
 263 function wfObjectToArray( $objOrArray, $recursive = true ) {
 264         $array = array();
 265         if ( is_object( $objOrArray ) ) {
 266                 $objOrArray = get_object_vars( $objOrArray );
 267         }
 268         foreach ( $objOrArray as $key => $value ) {
 269                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 270                         $value = wfObjectToArray( $value );
 271                 }
 272
 273                 $array[$key] = $value;
 274         }
 275
 276         return $array;
 277 }
 278
 279 /**
 280  * Wrapper around array_map() which also taints variables
 281  *
 282  * @param  $function Callback
 283  * @param  $input Array
 284  * @return Array
 285  */
 286 function wfArrayMap( $function, $input ) {
 287         $ret = array_map( $function, $input );
 288         foreach ( $ret as $key => $value ) {
 289                 $taint = istainted( $input[$key] );
 290                 if ( $taint ) {
 291                         taint( $ret[$key], $taint );
 292                 }
 293         }
 294         return $ret;
 295 }
 296
 297 /**
 298  * Get a random decimal value between 0 and 1, in a way
 299  * not likely to give duplicate values for any realistic
 300  * number of articles.
 301  *
 302  * @return string
 303  */
 304 function wfRandom() {
 305         # The maximum random value is "only" 2^31-1, so get two random
 306         # values to reduce the chance of dupes
 307         $max = mt_getrandmax() + 1;
 308         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 309                 / $max / $max, 12, '.', '' );
 310         return $rand;
 311 }
 312
 313 /**
 314  * Get a random string containing a number of pseudo-random hex
 315  * characters.
 316  * @note This is not secure, if you are trying to generate some sort
 317  *       of token please use MWCryptRand instead.
 318  *
 319  * @param int $length The length of the string to generate
 320  * @return String
 321  * @since 1.20
 322  */
 323 function wfRandomString( $length = 32 ) {
 324         $str = '';
 325         while ( strlen( $str ) < $length ) {
 326                 $str .= dechex( mt_rand() );
 327         }
 328         return substr( $str, 0, $length );
 329 }
 330
 331 /**
 332  * We want some things to be included as literal characters in our title URLs
 333  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 334  * all of the following should be safe:
 335  *
 336  * ;:@&=$-_.+!*'(),
 337  *
 338  * But + is not safe because it's used to indicate a space; &= are only safe in
 339  * paths and not in queries (and we don't distinguish here); ' seems kind of
 340  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 341  * is reserved, we don't care.  So the list we unescape is:
 342  *
 343  * ;:@$!*(),/
 344  *
 345  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 346  * so no fancy : for IIS7.
 347  *
 348  * %2F in the page titles seems to fatally break for some reason.
 349  *
 350  * @param $s String:
 351  * @return string
 352  */
 353 function wfUrlencode( $s ) {
 354         static $needle;
 355         if ( is_null( $s ) ) {
 356                 $needle = null;
 357                 return '';
 358         }
 359
 360         if ( is_null( $needle ) ) {
 361                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 362                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param array $array1 ( String|Array )
 383  * @param array $array2 ( String|Array )
 384  * @param $prefix String
 385  * @return String
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( !is_null( $value ) && $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 }
 416                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                         }
 418                 }
 419         }
 420         return $cgi;
 421 }
 422
 423 /**
 424  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 425  * its argument and returns the same string in array form.  This allows compatibility
 426  * with legacy functions that accept raw query strings instead of nice
 427  * arrays.  Of course, keys and values are urldecode()d.
 428  *
 429  * @param string $query query string
 430  * @return array Array version of input
 431  */
 432 function wfCgiToArray( $query ) {
 433         if ( isset( $query[0] ) && $query[0] == '?' ) {
 434                 $query = substr( $query, 1 );
 435         }
 436         $bits = explode( '&', $query );
 437         $ret = array();
 438         foreach ( $bits as $bit ) {
 439                 if ( $bit === '' ) {
 440                         continue;
 441                 }
 442                 if ( strpos( $bit, '=' ) === false ) {
 443                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 444                         $key = $bit;
 445                         $value = '';
 446                 } else {
 447                         list( $key, $value ) = explode( '=', $bit );
 448                 }
 449                 $key = urldecode( $key );
 450                 $value = urldecode( $value );
 451                 if ( strpos( $key, '[' ) !== false ) {
 452                         $keys = array_reverse( explode( '[', $key ) );
 453                         $key = array_pop( $keys );
 454                         $temp = $value;
 455                         foreach ( $keys as $k ) {
 456                                 $k = substr( $k, 0, -1 );
 457                                 $temp = array( $k => $temp );
 458                         }
 459                         if ( isset( $ret[$key] ) ) {
 460                                 $ret[$key] = array_merge( $ret[$key], $temp );
 461                         } else {
 462                                 $ret[$key] = $temp;
 463                         }
 464                 } else {
 465                         $ret[$key] = $value;
 466                 }
 467         }
 468         return $ret;
 469 }
 470
 471 /**
 472  * Append a query string to an existing URL, which may or may not already
 473  * have query string parameters already. If so, they will be combined.
 474  *
 475  * @param $url String
 476  * @param $query Mixed: string or associative array
 477  * @return string
 478  */
 479 function wfAppendQuery( $url, $query ) {
 480         if ( is_array( $query ) ) {
 481                 $query = wfArrayToCgi( $query );
 482         }
 483         if ( $query != '' ) {
 484                 if ( false === strpos( $url, '?' ) ) {
 485                         $url .= '?';
 486                 } else {
 487                         $url .= '&';
 488                 }
 489                 $url .= $query;
 490         }
 491         return $url;
 492 }
 493
 494 /**
 495  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 496  * is correct.
 497  *
 498  * The meaning of the PROTO_* constants is as follows:
 499  * PROTO_HTTP: Output a URL starting with http://
 500  * PROTO_HTTPS: Output a URL starting with https://
 501  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 502  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 503  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 504  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 505  *
 506  * @todo this won't work with current-path-relative URLs
 507  * like "subdir/foo.html", etc.
 508  *
 509  * @param string $url either fully-qualified or a local path + query
 510  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 511  *                             protocol to use if $url or $wgServer is
 512  *                             protocol-relative
 513  * @return string Fully-qualified URL, current-path-relative URL or false if
 514  *                no valid URL can be constructed
 515  */
 516 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 517         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 518         $serverUrl = $wgServer;
 519         if ( $defaultProto === PROTO_CANONICAL ) {
 520                 $serverUrl = $wgCanonicalServer;
 521         }
 522         // Make $wgInternalServer fall back to $wgServer if not set
 523         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 524                 $serverUrl = $wgInternalServer;
 525         }
 526         if ( $defaultProto === PROTO_CURRENT ) {
 527                 $defaultProto = WebRequest::detectProtocol() . '://';
 528         }
 529
 530         // Analyze $serverUrl to obtain its protocol
 531         $bits = wfParseUrl( $serverUrl );
 532         $serverHasProto = $bits && $bits['scheme'] != '';
 533
 534         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 535                 if ( $serverHasProto ) {
 536                         $defaultProto = $bits['scheme'] . '://';
 537                 } else {
 538                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 539                         // Fall back to HTTP in this ridiculous case
 540                         $defaultProto = PROTO_HTTP;
 541                 }
 542         }
 543
 544         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 545
 546         if ( substr( $url, 0, 2 ) == '//' ) {
 547                 $url = $defaultProtoWithoutSlashes . $url;
 548         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 549                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 550                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 551         }
 552
 553         $bits = wfParseUrl( $url );
 554         if ( $bits && isset( $bits['path'] ) ) {
 555                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 556                 return wfAssembleUrl( $bits );
 557         } elseif ( $bits ) {
 558                 # No path to expand
 559                 return $url;
 560         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 561                 # URL is a relative path
 562                 return wfRemoveDotSegments( $url );
 563         }
 564
 565         # Expanded URL is not valid.
 566         return false;
 567 }
 568
 569 /**
 570  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 571  * if you need to edit part of a URL and put it back together.
 572  *
 573  * This is the basic structure used (brackets contain keys for $urlParts):
 574  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 575  *
 576  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 577  *
 578  * @since 1.19
 579  * @param array $urlParts URL parts, as output from wfParseUrl
 580  * @return string URL assembled from its component parts
 581  */
 582 function wfAssembleUrl( $urlParts ) {
 583         $result = '';
 584
 585         if ( isset( $urlParts['delimiter'] ) ) {
 586                 if ( isset( $urlParts['scheme'] ) ) {
 587                         $result .= $urlParts['scheme'];
 588                 }
 589
 590                 $result .= $urlParts['delimiter'];
 591         }
 592
 593         if ( isset( $urlParts['host'] ) ) {
 594                 if ( isset( $urlParts['user'] ) ) {
 595                         $result .= $urlParts['user'];
 596                         if ( isset( $urlParts['pass'] ) ) {
 597                                 $result .= ':' . $urlParts['pass'];
 598                         }
 599                         $result .= '@';
 600                 }
 601
 602                 $result .= $urlParts['host'];
 603
 604                 if ( isset( $urlParts['port'] ) ) {
 605                         $result .= ':' . $urlParts['port'];
 606                 }
 607         }
 608
 609         if ( isset( $urlParts['path'] ) ) {
 610                 $result .= $urlParts['path'];
 611         }
 612
 613         if ( isset( $urlParts['query'] ) ) {
 614                 $result .= '?' . $urlParts['query'];
 615         }
 616
 617         if ( isset( $urlParts['fragment'] ) ) {
 618                 $result .= '#' . $urlParts['fragment'];
 619         }
 620
 621         return $result;
 622 }
 623
 624 /**
 625  * Remove all dot-segments in the provided URL path.  For example,
 626  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 627  * RFC3986 section 5.2.4.
 628  *
 629  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 630  *
 631  * @param string $urlPath URL path, potentially containing dot-segments
 632  * @return string URL path with all dot-segments removed
 633  */
 634 function wfRemoveDotSegments( $urlPath ) {
 635         $output = '';
 636         $inputOffset = 0;
 637         $inputLength = strlen( $urlPath );
 638
 639         while ( $inputOffset < $inputLength ) {
 640                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 641                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 642                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 643                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 644                 $trimOutput = false;
 645
 646                 if ( $prefixLengthTwo == './' ) {
 647                         # Step A, remove leading "./"
 648                         $inputOffset += 2;
 649                 } elseif ( $prefixLengthThree == '../' ) {
 650                         # Step A, remove leading "../"
 651                         $inputOffset += 3;
 652                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 653                         # Step B, replace leading "/.$" with "/"
 654                         $inputOffset += 1;
 655                         $urlPath[$inputOffset] = '/';
 656                 } elseif ( $prefixLengthThree == '/./' ) {
 657                         # Step B, replace leading "/./" with "/"
 658                         $inputOffset += 2;
 659                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 660                         # Step C, replace leading "/..$" with "/" and
 661                         # remove last path component in output
 662                         $inputOffset += 2;
 663                         $urlPath[$inputOffset] = '/';
 664                         $trimOutput = true;
 665                 } elseif ( $prefixLengthFour == '/../' ) {
 666                         # Step C, replace leading "/../" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 3;
 669                         $trimOutput = true;
 670                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 671                         # Step D, remove "^.$"
 672                         $inputOffset += 1;
 673                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 674                         # Step D, remove "^..$"
 675                         $inputOffset += 2;
 676                 } else {
 677                         # Step E, move leading path segment to output
 678                         if ( $prefixLengthOne == '/' ) {
 679                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 680                         } else {
 681                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 682                         }
 683                         if ( $slashPos === false ) {
 684                                 $output .= substr( $urlPath, $inputOffset );
 685                                 $inputOffset = $inputLength;
 686                         } else {
 687                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 688                                 $inputOffset += $slashPos - $inputOffset;
 689                         }
 690                 }
 691
 692                 if ( $trimOutput ) {
 693                         $slashPos = strrpos( $output, '/' );
 694                         if ( $slashPos === false ) {
 695                                 $output = '';
 696                         } else {
 697                                 $output = substr( $output, 0, $slashPos );
 698                         }
 699                 }
 700         }
 701
 702         return $output;
 703 }
 704
 705 /**
 706  * Returns a regular expression of url protocols
 707  *
 708  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 709  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 710  * @return String
 711  */
 712 function wfUrlProtocols( $includeProtocolRelative = true ) {
 713         global $wgUrlProtocols;
 714
 715         // Cache return values separately based on $includeProtocolRelative
 716         static $withProtRel = null, $withoutProtRel = null;
 717         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 718         if ( !is_null( $cachedValue ) ) {
 719                 return $cachedValue;
 720         }
 721
 722         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 723         // with LocalSettings files from 1.5
 724         if ( is_array( $wgUrlProtocols ) ) {
 725                 $protocols = array();
 726                 foreach ( $wgUrlProtocols as $protocol ) {
 727                         // Filter out '//' if !$includeProtocolRelative
 728                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 729                                 $protocols[] = preg_quote( $protocol, '/' );
 730                         }
 731                 }
 732
 733                 $retval = implode( '|', $protocols );
 734         } else {
 735                 // Ignore $includeProtocolRelative in this case
 736                 // This case exists for pre-1.6 compatibility, and we can safely assume
 737                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 738                 // URLs weren't supported until 1.18
 739                 $retval = $wgUrlProtocols;
 740         }
 741
 742         // Cache return value
 743         if ( $includeProtocolRelative ) {
 744                 $withProtRel = $retval;
 745         } else {
 746                 $withoutProtRel = $retval;
 747         }
 748         return $retval;
 749 }
 750
 751 /**
 752  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 753  * you need a regex that matches all URL protocols but does not match protocol-
 754  * relative URLs
 755  * @return String
 756  */
 757 function wfUrlProtocolsWithoutProtRel() {
 758         return wfUrlProtocols( false );
 759 }
 760
 761 /**
 762  * parse_url() work-alike, but non-broken.  Differences:
 763  *
 764  * 1) Does not raise warnings on bad URLs (just returns false)
 765  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 766  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 767  *
 768  * @param string $url a URL to parse
 769  * @return Array: bits of the URL in an associative array, per PHP docs
 770  */
 771 function wfParseUrl( $url ) {
 772         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 773
 774         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 775         // way to handle them is to just prepend 'http:' and strip the protocol out later
 776         $wasRelative = substr( $url, 0, 2 ) == '//';
 777         if ( $wasRelative ) {
 778                 $url = "http:$url";
 779         }
 780         wfSuppressWarnings();
 781         $bits = parse_url( $url );
 782         wfRestoreWarnings();
 783         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 784         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 785         if ( !$bits || !isset( $bits['scheme'] ) ) {
 786                 return false;
 787         }
 788
 789         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 790         $bits['scheme'] = strtolower( $bits['scheme'] );
 791
 792         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 793         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 794                 $bits['delimiter'] = '://';
 795         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 796                 $bits['delimiter'] = ':';
 797                 // parse_url detects for news: and mailto: the host part of an url as path
 798                 // We have to correct this wrong detection
 799                 if ( isset( $bits['path'] ) ) {
 800                         $bits['host'] = $bits['path'];
 801                         $bits['path'] = '';
 802                 }
 803         } else {
 804                 return false;
 805         }
 806
 807         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 808         if ( !isset( $bits['host'] ) ) {
 809                 $bits['host'] = '';
 810
 811                 // bug 45069
 812                 if ( isset( $bits['path'] ) ) {
 813                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 814                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 815                                 $bits['path'] = '/' . $bits['path'];
 816                         }
 817                 } else {
 818                         $bits['path'] = '';
 819                 }
 820         }
 821
 822         // If the URL was protocol-relative, fix scheme and delimiter
 823         if ( $wasRelative ) {
 824                 $bits['scheme'] = '';
 825                 $bits['delimiter'] = '//';
 826         }
 827         return $bits;
 828 }
 829
 830 /**
 831  * Take a URL, make sure it's expanded to fully qualified, and replace any
 832  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 833  * for more compact display and legibility for local audiences.
 834  *
 835  * @todo handle punycode domains too
 836  *
 837  * @param $url string
 838  * @return string
 839  */
 840 function wfExpandIRI( $url ) {
 841         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 842 }
 843
 844 /**
 845  * Private callback for wfExpandIRI
 846  * @param array $matches
 847  * @return string
 848  */
 849 function wfExpandIRI_callback( $matches ) {
 850         return urldecode( $matches[1] );
 851 }
 852
 853 /**
 854  * Make URL indexes, appropriate for the el_index field of externallinks.
 855  *
 856  * @param $url String
 857  * @return array
 858  */
 859 function wfMakeUrlIndexes( $url ) {
 860         $bits = wfParseUrl( $url );
 861
 862         // Reverse the labels in the hostname, convert to lower case
 863         // For emails reverse domainpart only
 864         if ( $bits['scheme'] == 'mailto' ) {
 865                 $mailparts = explode( '@', $bits['host'], 2 );
 866                 if ( count( $mailparts ) === 2 ) {
 867                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 868                 } else {
 869                         // No domain specified, don't mangle it
 870                         $domainpart = '';
 871                 }
 872                 $reversedHost = $domainpart . '@' . $mailparts[0];
 873         } else {
 874                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 875         }
 876         // Add an extra dot to the end
 877         // Why? Is it in wrong place in mailto links?
 878         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 879                 $reversedHost .= '.';
 880         }
 881         // Reconstruct the pseudo-URL
 882         $prot = $bits['scheme'];
 883         $index = $prot . $bits['delimiter'] . $reversedHost;
 884         // Leave out user and password. Add the port, path, query and fragment
 885         if ( isset( $bits['port'] ) ) {
 886                 $index .= ':' . $bits['port'];
 887         }
 888         if ( isset( $bits['path'] ) ) {
 889                 $index .= $bits['path'];
 890         } else {
 891                 $index .= '/';
 892         }
 893         if ( isset( $bits['query'] ) ) {
 894                 $index .= '?' . $bits['query'];
 895         }
 896         if ( isset( $bits['fragment'] ) ) {
 897                 $index .= '#' . $bits['fragment'];
 898         }
 899
 900         if ( $prot == '' ) {
 901                 return array( "http:$index", "https:$index" );
 902         } else {
 903                 return array( $index );
 904         }
 905 }
 906
 907 /**
 908  * Check whether a given URL has a domain that occurs in a given set of domains
 909  * @param string $url URL
 910  * @param array $domains Array of domains (strings)
 911  * @return bool True if the host part of $url ends in one of the strings in $domains
 912  */
 913 function wfMatchesDomainList( $url, $domains ) {
 914         $bits = wfParseUrl( $url );
 915         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 916                 foreach ( (array)$domains as $domain ) {
 917                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 918                         // We should use something that interprets dots instead
 919                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 920                                 return true;
 921                         }
 922                 }
 923         }
 924         return false;
 925 }
 926
 927 /**
 928  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 929  * In normal operation this is a NOP.
 930  *
 931  * Controlling globals:
 932  * $wgDebugLogFile - points to the log file
 933  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 934  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 935  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 936  *
 937  * @param $text String
 938  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 939  */
 940 function wfDebug( $text, $logonly = false ) {
 941         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 942
 943         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 944                 return;
 945         }
 946
 947         $timer = wfDebugTimer();
 948         if ( $timer !== '' ) {
 949                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 950         }
 951
 952         if ( !$logonly ) {
 953                 MWDebug::debugMsg( $text );
 954         }
 955
 956         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 957                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 958                         # Strip unprintables; they can switch terminal modes when binary data
 959                         # gets dumped, which is pretty annoying.
 960                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 961                         $text = $wgDebugLogPrefix . $text;
 962                         wfErrorLog( $text, $wgDebugLogFile );
 963                 }
 964         }
 965 }
 966
 967 /**
 968  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 969  * @return bool
 970  */
 971 function wfIsDebugRawPage() {
 972         static $cache;
 973         if ( $cache !== null ) {
 974                 return $cache;
 975         }
 976         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 977         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 978                 || (
 979                         isset( $_SERVER['SCRIPT_NAME'] )
 980                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 981                 ) )
 982         {
 983                 $cache = true;
 984         } else {
 985                 $cache = false;
 986         }
 987         return $cache;
 988 }
 989
 990 /**
 991  * Get microsecond timestamps for debug logs
 992  *
 993  * @return string
 994  */
 995 function wfDebugTimer() {
 996         global $wgDebugTimestamps, $wgRequestTime;
 997
 998         if ( !$wgDebugTimestamps ) {
 999                 return '';
1000         }
1001
1002         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1003         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1004         return "$prefix $mem  ";
1005 }
1006
1007 /**
1008  * Send a line giving PHP memory usage.
1009  *
1010  * @param bool $exact print exact values instead of kilobytes (default: false)
1011  */
1012 function wfDebugMem( $exact = false ) {
1013         $mem = memory_get_usage();
1014         if ( !$exact ) {
1015                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1016         } else {
1017                 $mem .= ' bytes';
1018         }
1019         wfDebug( "Memory usage: $mem\n" );
1020 }
1021
1022 /**
1023  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1024  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1025  *
1026  * @param $logGroup String
1027  * @param $text String
1028  * @param bool $public whether to log the event in the public log if no private
1029  *                     log file is specified, (default true)
1030  */
1031 function wfDebugLog( $logGroup, $text, $public = true ) {
1032         global $wgDebugLogGroups;
1033         $text = trim( $text ) . "\n";
1034         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1035                 $time = wfTimestamp( TS_DB );
1036                 $wiki = wfWikiID();
1037                 $host = wfHostname();
1038                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1039                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1040                 }
1041         } elseif ( $public === true ) {
1042                 wfDebug( "[$logGroup] $text", true );
1043         }
1044 }
1045
1046 /**
1047  * Log for database errors
1048  *
1049  * @param string $text database error message.
1050  */
1051 function wfLogDBError( $text ) {
1052         global $wgDBerrorLog, $wgDBerrorLogTZ;
1053         static $logDBErrorTimeZoneObject = null;
1054
1055         if ( $wgDBerrorLog ) {
1056                 $host = wfHostname();
1057                 $wiki = wfWikiID();
1058
1059                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1060                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1061                 }
1062
1063                 // Workaround for https://bugs.php.net/bug.php?id=52063
1064                 // Can be removed when min PHP > 5.3.2
1065                 if ( $logDBErrorTimeZoneObject === null ) {
1066                         $d = date_create( "now" );
1067                 } else {
1068                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1069                 }
1070
1071                 $date = $d->format( 'D M j G:i:s T Y' );
1072
1073                 $text = "$date\t$host\t$wiki\t$text";
1074                 wfErrorLog( $text, $wgDBerrorLog );
1075         }
1076 }
1077
1078 /**
1079  * Throws a warning that $function is deprecated
1080  *
1081  * @param $function String
1082  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1083  * @param string|bool $component Added in 1.19.
1084  * @param $callerOffset integer: How far up the call stack is the original
1085  *    caller. 2 = function that called the function that called
1086  *    wfDeprecated (Added in 1.20)
1087  *
1088  * @return null
1089  */
1090 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1091         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1092 }
1093
1094 /**
1095  * Send a warning either to the debug log or in a PHP error depending on
1096  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1097  *
1098  * @param string $msg message to send
1099  * @param $callerOffset Integer: number of items to go back in the backtrace to
1100  *        find the correct caller (1 = function calling wfWarn, ...)
1101  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1102  *        only used when $wgDevelopmentWarnings is true
1103  */
1104 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1105         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1106 }
1107
1108 /**
1109  * Send a warning as a PHP error and the debug log. This is intended for logging
1110  * warnings in production. For logging development warnings, use WfWarn instead.
1111  *
1112  * @param $msg String: message to send
1113  * @param $callerOffset Integer: number of items to go back in the backtrace to
1114  *        find the correct caller (1 = function calling wfLogWarning, ...)
1115  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1116  */
1117 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1118         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1119 }
1120
1121 /**
1122  * Log to a file without getting "file size exceeded" signals.
1123  *
1124  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1125  * send lines to the specified port, prefixed by the specified prefix and a space.
1126  *
1127  * @param $text String
1128  * @param string $file filename
1129  * @throws MWException
1130  */
1131 function wfErrorLog( $text, $file ) {
1132         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1133                 # Needs the sockets extension
1134                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1135                         // IPv6 bracketed host
1136                         $host = $m[2];
1137                         $port = intval( $m[3] );
1138                         $prefix = isset( $m[4] ) ? $m[4] : false;
1139                         $domain = AF_INET6;
1140                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1141                         $host = $m[2];
1142                         if ( !IP::isIPv4( $host ) ) {
1143                                 $host = gethostbyname( $host );
1144                         }
1145                         $port = intval( $m[3] );
1146                         $prefix = isset( $m[4] ) ? $m[4] : false;
1147                         $domain = AF_INET;
1148                 } else {
1149                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1150                 }
1151
1152                 // Clean it up for the multiplexer
1153                 if ( strval( $prefix ) !== '' ) {
1154                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1155
1156                         // Limit to 64KB
1157                         if ( strlen( $text ) > 65506 ) {
1158                                 $text = substr( $text, 0, 65506 );
1159                         }
1160
1161                         if ( substr( $text, -1 ) != "\n" ) {
1162                                 $text .= "\n";
1163                         }
1164                 } elseif ( strlen( $text ) > 65507 ) {
1165                         $text = substr( $text, 0, 65507 );
1166                 }
1167
1168                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1169                 if ( !$sock ) {
1170                         return;
1171                 }
1172
1173                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1174                 socket_close( $sock );
1175         } else {
1176                 wfSuppressWarnings();
1177                 $exists = file_exists( $file );
1178                 $size = $exists ? filesize( $file ) : false;
1179                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1180                         file_put_contents( $file, $text, FILE_APPEND );
1181                 }
1182                 wfRestoreWarnings();
1183         }
1184 }
1185
1186 /**
1187  * @todo document
1188  */
1189 function wfLogProfilingData() {
1190         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1191         global $wgProfileLimit, $wgUser;
1192
1193         StatCounter::singleton()->flush();
1194
1195         $profiler = Profiler::instance();
1196
1197         # Profiling must actually be enabled...
1198         if ( $profiler->isStub() ) {
1199                 return;
1200         }
1201
1202         // Get total page request time and only show pages that longer than
1203         // $wgProfileLimit time (default is 0)
1204         $elapsed = microtime( true ) - $wgRequestTime;
1205         if ( $elapsed <= $wgProfileLimit ) {
1206                 return;
1207         }
1208
1209         $profiler->logData();
1210
1211         // Check whether this should be logged in the debug file.
1212         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1213                 return;
1214         }
1215
1216         $forward = '';
1217         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1218                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1219         }
1220         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1221                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1222         }
1223         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1224                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1225         }
1226         if ( $forward ) {
1227                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1228         }
1229         // Don't load $wgUser at this late stage just for statistics purposes
1230         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1231         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1232                 $forward .= ' anon';
1233         }
1234
1235         // Command line script uses a FauxRequest object which does not have
1236         // any knowledge about an URL and throw an exception instead.
1237         try {
1238                 $requestUrl = $wgRequest->getRequestURL();
1239         } catch ( MWException $e ) {
1240                 $requestUrl = 'n/a';
1241         }
1242
1243         $log = sprintf( "%s\t%04.3f\t%s\n",
1244                 gmdate( 'YmdHis' ), $elapsed,
1245                 urldecode( $requestUrl . $forward ) );
1246
1247         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1248 }
1249
1250 /**
1251  * Increment a statistics counter
1252  *
1253  * @param $key String
1254  * @param $count Int
1255  * @return void
1256  */
1257 function wfIncrStats( $key, $count = 1 ) {
1258         StatCounter::singleton()->incr( $key, $count );
1259 }
1260
1261 /**
1262  * Check if the wiki read-only lock file is present. This can be used to lock
1263  * off editing functions, but doesn't guarantee that the database will not be
1264  * modified.
1265  *
1266  * @return bool
1267  */
1268 function wfReadOnly() {
1269         global $wgReadOnlyFile, $wgReadOnly;
1270
1271         if ( !is_null( $wgReadOnly ) ) {
1272                 return (bool)$wgReadOnly;
1273         }
1274         if ( $wgReadOnlyFile == '' ) {
1275                 return false;
1276         }
1277         // Set $wgReadOnly for faster access next time
1278         if ( is_file( $wgReadOnlyFile ) ) {
1279                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1280         } else {
1281                 $wgReadOnly = false;
1282         }
1283         return (bool)$wgReadOnly;
1284 }
1285
1286 /**
1287  * @return bool
1288  */
1289 function wfReadOnlyReason() {
1290         global $wgReadOnly;
1291         wfReadOnly();
1292         return $wgReadOnly;
1293 }
1294
1295 /**
1296  * Return a Language object from $langcode
1297  *
1298  * @param $langcode Mixed: either:
1299  *                  - a Language object
1300  *                  - code of the language to get the message for, if it is
1301  *                    a valid code create a language for that language, if
1302  *                    it is a string but not a valid code then make a basic
1303  *                    language object
1304  *                  - a boolean: if it's false then use the global object for
1305  *                    the current user's language (as a fallback for the old parameter
1306  *                    functionality), or if it is true then use global object
1307  *                    for the wiki's content language.
1308  * @return Language object
1309  */
1310 function wfGetLangObj( $langcode = false ) {
1311         # Identify which language to get or create a language object for.
1312         # Using is_object here due to Stub objects.
1313         if ( is_object( $langcode ) ) {
1314                 # Great, we already have the object (hopefully)!
1315                 return $langcode;
1316         }
1317
1318         global $wgContLang, $wgLanguageCode;
1319         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1320                 # $langcode is the language code of the wikis content language object.
1321                 # or it is a boolean and value is true
1322                 return $wgContLang;
1323         }
1324
1325         global $wgLang;
1326         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1327                 # $langcode is the language code of user language object.
1328                 # or it was a boolean and value is false
1329                 return $wgLang;
1330         }
1331
1332         $validCodes = array_keys( Language::fetchLanguageNames() );
1333         if ( in_array( $langcode, $validCodes ) ) {
1334                 # $langcode corresponds to a valid language.
1335                 return Language::factory( $langcode );
1336         }
1337
1338         # $langcode is a string, but not a valid language code; use content language.
1339         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1340         return $wgContLang;
1341 }
1342
1343 /**
1344  * Old function when $wgBetterDirectionality existed
1345  * All usage removed, wfUILang can be removed in near future
1346  *
1347  * @deprecated since 1.18
1348  * @return Language
1349  */
1350 function wfUILang() {
1351         wfDeprecated( __METHOD__, '1.18' );
1352         global $wgLang;
1353         return $wgLang;
1354 }
1355
1356 /**
1357  * This is the function for getting translated interface messages.
1358  *
1359  * @see Message class for documentation how to use them.
1360  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1361  *
1362  * This function replaces all old wfMsg* functions.
1363  *
1364  * @param $key \string Message key.
1365  * Varargs: normal message parameters.
1366  * @return Message
1367  * @since 1.17
1368  */
1369 function wfMessage( $key /*...*/) {
1370         $params = func_get_args();
1371         array_shift( $params );
1372         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1373                 $params = $params[0];
1374         }
1375         return new Message( $key, $params );
1376 }
1377
1378 /**
1379  * This function accepts multiple message keys and returns a message instance
1380  * for the first message which is non-empty. If all messages are empty then an
1381  * instance of the first message key is returned.
1382  * @param varargs: message keys
1383  * @return Message
1384  * @since 1.18
1385  */
1386 function wfMessageFallback( /*...*/ ) {
1387         $args = func_get_args();
1388         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1389 }
1390
1391 /**
1392  * Get a message from anywhere, for the current user language.
1393  *
1394  * Use wfMsgForContent() instead if the message should NOT
1395  * change depending on the user preferences.
1396  *
1397  * @deprecated since 1.18
1398  *
1399  * @param string $key lookup key for the message, usually
1400  *    defined in languages/Language.php
1401  *
1402  * Parameters to the message, which can be used to insert variable text into
1403  * it, can be passed to this function in the following formats:
1404  * - One per argument, starting at the second parameter
1405  * - As an array in the second parameter
1406  * These are not shown in the function definition.
1407  *
1408  * @return String
1409  */
1410 function wfMsg( $key ) {
1411         wfDeprecated( __METHOD__, '1.21' );
1412
1413         $args = func_get_args();
1414         array_shift( $args );
1415         return wfMsgReal( $key, $args );
1416 }
1417
1418 /**
1419  * Same as above except doesn't transform the message
1420  *
1421  * @deprecated since 1.18
1422  *
1423  * @param $key String
1424  * @return String
1425  */
1426 function wfMsgNoTrans( $key ) {
1427         wfDeprecated( __METHOD__, '1.21' );
1428
1429         $args = func_get_args();
1430         array_shift( $args );
1431         return wfMsgReal( $key, $args, true, false, false );
1432 }
1433
1434 /**
1435  * Get a message from anywhere, for the current global language
1436  * set with $wgLanguageCode.
1437  *
1438  * Use this if the message should NOT change dependent on the
1439  * language set in the user's preferences. This is the case for
1440  * most text written into logs, as well as link targets (such as
1441  * the name of the copyright policy page). Link titles, on the
1442  * other hand, should be shown in the UI language.
1443  *
1444  * Note that MediaWiki allows users to change the user interface
1445  * language in their preferences, but a single installation
1446  * typically only contains content in one language.
1447  *
1448  * Be wary of this distinction: If you use wfMsg() where you should
1449  * use wfMsgForContent(), a user of the software may have to
1450  * customize potentially hundreds of messages in
1451  * order to, e.g., fix a link in every possible language.
1452  *
1453  * @deprecated since 1.18
1454  *
1455  * @param string $key lookup key for the message, usually
1456  *     defined in languages/Language.php
1457  * @return String
1458  */
1459 function wfMsgForContent( $key ) {
1460         wfDeprecated( __METHOD__, '1.21' );
1461
1462         global $wgForceUIMsgAsContentMsg;
1463         $args = func_get_args();
1464         array_shift( $args );
1465         $forcontent = true;
1466         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1467                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1468         {
1469                 $forcontent = false;
1470         }
1471         return wfMsgReal( $key, $args, true, $forcontent );
1472 }
1473
1474 /**
1475  * Same as above except doesn't transform the message
1476  *
1477  * @deprecated since 1.18
1478  *
1479  * @param $key String
1480  * @return String
1481  */
1482 function wfMsgForContentNoTrans( $key ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         global $wgForceUIMsgAsContentMsg;
1486         $args = func_get_args();
1487         array_shift( $args );
1488         $forcontent = true;
1489         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1490                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1491         {
1492                 $forcontent = false;
1493         }
1494         return wfMsgReal( $key, $args, true, $forcontent, false );
1495 }
1496
1497 /**
1498  * Really get a message
1499  *
1500  * @deprecated since 1.18
1501  *
1502  * @param string $key key to get.
1503  * @param $args
1504  * @param $useDB Boolean
1505  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1506  * @param $transform Boolean: Whether or not to transform the message.
1507  * @return String: the requested message.
1508  */
1509 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1510         wfDeprecated( __METHOD__, '1.21' );
1511
1512         wfProfileIn( __METHOD__ );
1513         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1514         $message = wfMsgReplaceArgs( $message, $args );
1515         wfProfileOut( __METHOD__ );
1516         return $message;
1517 }
1518
1519 /**
1520  * Fetch a message string value, but don't replace any keys yet.
1521  *
1522  * @deprecated since 1.18
1523  *
1524  * @param $key String
1525  * @param $useDB Bool
1526  * @param string $langCode Code of the language to get the message for, or
1527  *                  behaves as a content language switch if it is a boolean.
1528  * @param $transform Boolean: whether to parse magic words, etc.
1529  * @return string
1530  */
1531 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1532         wfDeprecated( __METHOD__, '1.21' );
1533
1534         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1535
1536         $cache = MessageCache::singleton();
1537         $message = $cache->get( $key, $useDB, $langCode );
1538         if ( $message === false ) {
1539                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1540         } elseif ( $transform ) {
1541                 $message = $cache->transform( $message );
1542         }
1543         return $message;
1544 }
1545
1546 /**
1547  * Replace message parameter keys on the given formatted output.
1548  *
1549  * @param $message String
1550  * @param $args Array
1551  * @return string
1552  * @private
1553  */
1554 function wfMsgReplaceArgs( $message, $args ) {
1555         # Fix windows line-endings
1556         # Some messages are split with explode("\n", $msg)
1557         $message = str_replace( "\r", '', $message );
1558
1559         // Replace arguments
1560         if ( count( $args ) ) {
1561                 if ( is_array( $args[0] ) ) {
1562                         $args = array_values( $args[0] );
1563                 }
1564                 $replacementKeys = array();
1565                 foreach ( $args as $n => $param ) {
1566                         $replacementKeys['$' . ( $n + 1 )] = $param;
1567                 }
1568                 $message = strtr( $message, $replacementKeys );
1569         }
1570
1571         return $message;
1572 }
1573
1574 /**
1575  * Return an HTML-escaped version of a message.
1576  * Parameter replacements, if any, are done *after* the HTML-escaping,
1577  * so parameters may contain HTML (eg links or form controls). Be sure
1578  * to pre-escape them if you really do want plaintext, or just wrap
1579  * the whole thing in htmlspecialchars().
1580  *
1581  * @deprecated since 1.18
1582  *
1583  * @param $key String
1584  * @param string ... parameters
1585  * @return string
1586  */
1587 function wfMsgHtml( $key ) {
1588         wfDeprecated( __METHOD__, '1.21' );
1589
1590         $args = func_get_args();
1591         array_shift( $args );
1592         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1593 }
1594
1595 /**
1596  * Return an HTML version of message
1597  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1598  * so parameters may contain HTML (eg links or form controls). Be sure
1599  * to pre-escape them if you really do want plaintext, or just wrap
1600  * the whole thing in htmlspecialchars().
1601  *
1602  * @deprecated since 1.18
1603  *
1604  * @param $key String
1605  * @param string ... parameters
1606  * @return string
1607  */
1608 function wfMsgWikiHtml( $key ) {
1609         wfDeprecated( __METHOD__, '1.21' );
1610
1611         $args = func_get_args();
1612         array_shift( $args );
1613         return wfMsgReplaceArgs(
1614                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1615                 /* can't be set to false */ true, /* interface */ true )->getText(),
1616                 $args );
1617 }
1618
1619 /**
1620  * Returns message in the requested format
1621  *
1622  * @deprecated since 1.18
1623  *
1624  * @param string $key key of the message
1625  * @param array $options processing rules. Can take the following options:
1626  *   <i>parse</i>: parses wikitext to HTML
1627  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1628  *       p's added by parser or tidy
1629  *   <i>escape</i>: filters message through htmlspecialchars
1630  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1631  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1632  *   <i>parsemag</i>: transform the message using magic phrases
1633  *   <i>content</i>: fetch message for content language instead of interface
1634  * Also can accept a single associative argument, of the form 'language' => 'xx':
1635  *   <i>language</i>: Language object or language code to fetch message for
1636  *       (overridden by <i>content</i>).
1637  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1638  *
1639  * @return String
1640  */
1641 function wfMsgExt( $key, $options ) {
1642         wfDeprecated( __METHOD__, '1.21' );
1643
1644         $args = func_get_args();
1645         array_shift( $args );
1646         array_shift( $args );
1647         $options = (array)$options;
1648
1649         foreach ( $options as $arrayKey => $option ) {
1650                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1651                         # An unknown index, neither numeric nor "language"
1652                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1653                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1654                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1655                 'replaceafter', 'parsemag', 'content' ) ) ) {
1656                         # A numeric index with unknown value
1657                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1658                 }
1659         }
1660
1661         if ( in_array( 'content', $options, true ) ) {
1662                 $forContent = true;
1663                 $langCode = true;
1664                 $langCodeObj = null;
1665         } elseif ( array_key_exists( 'language', $options ) ) {
1666                 $forContent = false;
1667                 $langCode = wfGetLangObj( $options['language'] );
1668                 $langCodeObj = $langCode;
1669         } else {
1670                 $forContent = false;
1671                 $langCode = false;
1672                 $langCodeObj = null;
1673         }
1674
1675         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1676
1677         if ( !in_array( 'replaceafter', $options, true ) ) {
1678                 $string = wfMsgReplaceArgs( $string, $args );
1679         }
1680
1681         $messageCache = MessageCache::singleton();
1682         $parseInline = in_array( 'parseinline', $options, true );
1683         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1684                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1685                 if ( $string instanceof ParserOutput ) {
1686                         $string = $string->getText();
1687                 }
1688
1689                 if ( $parseInline ) {
1690                         $m = array();
1691                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1692                                 $string = $m[1];
1693                         }
1694                 }
1695         } elseif ( in_array( 'parsemag', $options, true ) ) {
1696                 $string = $messageCache->transform( $string,
1697                                 !$forContent, $langCodeObj );
1698         }
1699
1700         if ( in_array( 'escape', $options, true ) ) {
1701                 $string = htmlspecialchars ( $string );
1702         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1703                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1704         }
1705
1706         if ( in_array( 'replaceafter', $options, true ) ) {
1707                 $string = wfMsgReplaceArgs( $string, $args );
1708         }
1709
1710         return $string;
1711 }
1712
1713 /**
1714  * Since wfMsg() and co suck, they don't return false if the message key they
1715  * looked up didn't exist but a XHTML string, this function checks for the
1716  * nonexistence of messages by checking the MessageCache::get() result directly.
1717  *
1718  * @deprecated since 1.18. Use Message::isDisabled().
1719  *
1720  * @param $key      String: the message key looked up
1721  * @return Boolean True if the message *doesn't* exist.
1722  */
1723 function wfEmptyMsg( $key ) {
1724         wfDeprecated( __METHOD__, '1.21' );
1725
1726         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1727 }
1728
1729 /**
1730  * Throw a debugging exception. This function previously once exited the process,
1731  * but now throws an exception instead, with similar results.
1732  *
1733  * @param string $msg message shown when dying.
1734  * @throws MWException
1735  */
1736 function wfDebugDieBacktrace( $msg = '' ) {
1737         throw new MWException( $msg );
1738 }
1739
1740 /**
1741  * Fetch server name for use in error reporting etc.
1742  * Use real server name if available, so we know which machine
1743  * in a server farm generated the current page.
1744  *
1745  * @return string
1746  */
1747 function wfHostname() {
1748         static $host;
1749         if ( is_null( $host ) ) {
1750
1751                 # Hostname overriding
1752                 global $wgOverrideHostname;
1753                 if ( $wgOverrideHostname !== false ) {
1754                         # Set static and skip any detection
1755                         $host = $wgOverrideHostname;
1756                         return $host;
1757                 }
1758
1759                 if ( function_exists( 'posix_uname' ) ) {
1760                         // This function not present on Windows
1761                         $uname = posix_uname();
1762                 } else {
1763                         $uname = false;
1764                 }
1765                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1766                         $host = $uname['nodename'];
1767                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1768                         # Windows computer name
1769                         $host = getenv( 'COMPUTERNAME' );
1770                 } else {
1771                         # This may be a virtual server.
1772                         $host = $_SERVER['SERVER_NAME'];
1773                 }
1774         }
1775         return $host;
1776 }
1777
1778 /**
1779  * Returns a HTML comment with the elapsed time since request.
1780  * This method has no side effects.
1781  *
1782  * @return string
1783  */
1784 function wfReportTime() {
1785         global $wgRequestTime, $wgShowHostnames;
1786
1787         $elapsed = microtime( true ) - $wgRequestTime;
1788
1789         return $wgShowHostnames
1790                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1791                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1792 }
1793
1794 /**
1795  * Safety wrapper for debug_backtrace().
1796  *
1797  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1798  * murky circumstances, which may be triggered in part by stub objects
1799  * or other fancy talking'.
1800  *
1801  * Will return an empty array if Zend Optimizer is detected or if
1802  * debug_backtrace is disabled, otherwise the output from
1803  * debug_backtrace() (trimmed).
1804  *
1805  * @param int $limit This parameter can be used to limit the number of stack frames returned
1806  *
1807  * @return array of backtrace information
1808  */
1809 function wfDebugBacktrace( $limit = 0 ) {
1810         static $disabled = null;
1811
1812         if ( extension_loaded( 'Zend Optimizer' ) ) {
1813                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1814                 return array();
1815         }
1816
1817         if ( is_null( $disabled ) ) {
1818                 $disabled = false;
1819                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1820                 $functions = array_map( 'trim', $functions );
1821                 $functions = array_map( 'strtolower', $functions );
1822                 if ( in_array( 'debug_backtrace', $functions ) ) {
1823                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1824                         $disabled = true;
1825                 }
1826         }
1827         if ( $disabled ) {
1828                 return array();
1829         }
1830
1831         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1832                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1833         } else {
1834                 return array_slice( debug_backtrace(), 1 );
1835         }
1836 }
1837
1838 /**
1839  * Get a debug backtrace as a string
1840  *
1841  * @return string
1842  */
1843 function wfBacktrace() {
1844         global $wgCommandLineMode;
1845
1846         if ( $wgCommandLineMode ) {
1847                 $msg = '';
1848         } else {
1849                 $msg = "<ul>\n";
1850         }
1851         $backtrace = wfDebugBacktrace();
1852         foreach ( $backtrace as $call ) {
1853                 if ( isset( $call['file'] ) ) {
1854                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1855                         $file = $f[count( $f ) - 1];
1856                 } else {
1857                         $file = '-';
1858                 }
1859                 if ( isset( $call['line'] ) ) {
1860                         $line = $call['line'];
1861                 } else {
1862                         $line = '-';
1863                 }
1864                 if ( $wgCommandLineMode ) {
1865                         $msg .= "$file line $line calls ";
1866                 } else {
1867                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1868                 }
1869                 if ( !empty( $call['class'] ) ) {
1870                         $msg .= $call['class'] . $call['type'];
1871                 }
1872                 $msg .= $call['function'] . '()';
1873
1874                 if ( $wgCommandLineMode ) {
1875                         $msg .= "\n";
1876                 } else {
1877                         $msg .= "</li>\n";
1878                 }
1879         }
1880         if ( $wgCommandLineMode ) {
1881                 $msg .= "\n";
1882         } else {
1883                 $msg .= "</ul>\n";
1884         }
1885
1886         return $msg;
1887 }
1888
1889 /**
1890  * Get the name of the function which called this function
1891  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1892  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1893  * wfGetCaller( 3 ) is the parent of that.
1894  *
1895  * @param $level Int
1896  * @return string
1897  */
1898 function wfGetCaller( $level = 2 ) {
1899         $backtrace = wfDebugBacktrace( $level + 1 );
1900         if ( isset( $backtrace[$level] ) ) {
1901                 return wfFormatStackFrame( $backtrace[$level] );
1902         } else {
1903                 return 'unknown';
1904         }
1905 }
1906
1907 /**
1908  * Return a string consisting of callers in the stack. Useful sometimes
1909  * for profiling specific points.
1910  *
1911  * @param int $limit The maximum depth of the stack frame to return, or false for
1912  *               the entire stack.
1913  * @return String
1914  */
1915 function wfGetAllCallers( $limit = 3 ) {
1916         $trace = array_reverse( wfDebugBacktrace() );
1917         if ( !$limit || $limit > count( $trace ) - 1 ) {
1918                 $limit = count( $trace ) - 1;
1919         }
1920         $trace = array_slice( $trace, -$limit - 1, $limit );
1921         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1922 }
1923
1924 /**
1925  * Return a string representation of frame
1926  *
1927  * @param $frame Array
1928  * @return string
1929  */
1930 function wfFormatStackFrame( $frame ) {
1931         return isset( $frame['class'] ) ?
1932                 $frame['class'] . '::' . $frame['function'] :
1933                 $frame['function'];
1934 }
1935
1936 /* Some generic result counters, pulled out of SearchEngine */
1937
1938 /**
1939  * @todo document
1940  *
1941  * @param $offset Int
1942  * @param $limit Int
1943  * @return String
1944  */
1945 function wfShowingResults( $offset, $limit ) {
1946         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1947 }
1948
1949 /**
1950  * Generate (prev x| next x) (20|50|100...) type links for paging
1951  *
1952  * @param $offset String
1953  * @param $limit Integer
1954  * @param $link String
1955  * @param string $query optional URL query parameter string
1956  * @param bool $atend optional param for specified if this is the last page
1957  * @return String
1958  * @deprecated in 1.19; use Language::viewPrevNext() instead
1959  */
1960 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1961         wfDeprecated( __METHOD__, '1.19' );
1962
1963         global $wgLang;
1964
1965         $query = wfCgiToArray( $query );
1966
1967         if ( is_object( $link ) ) {
1968                 $title = $link;
1969         } else {
1970                 $title = Title::newFromText( $link );
1971                 if ( is_null( $title ) ) {
1972                         return false;
1973                 }
1974         }
1975
1976         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1977 }
1978
1979 /**
1980  * Make a list item, used by various special pages
1981  *
1982  * @param string $page Page link
1983  * @param string $details Text between brackets
1984  * @param $oppositedm Boolean   Add the direction mark opposite to your
1985  *                                                              language, to display text properly
1986  * @return String
1987  * @deprecated since 1.19; use Language::specialList() instead
1988  */
1989 function wfSpecialList( $page, $details, $oppositedm = true ) {
1990         wfDeprecated( __METHOD__, '1.19' );
1991
1992         global $wgLang;
1993         return $wgLang->specialList( $page, $details, $oppositedm );
1994 }
1995
1996 /**
1997  * @todo document
1998  * @todo FIXME: We may want to blacklist some broken browsers
1999  *
2000  * @param $force Bool
2001  * @return bool Whereas client accept gzip compression
2002  */
2003 function wfClientAcceptsGzip( $force = false ) {
2004         static $result = null;
2005         if ( $result === null || $force ) {
2006                 $result = false;
2007                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2008                         # @todo FIXME: We may want to blacklist some broken browsers
2009                         $m = array();
2010                         if ( preg_match(
2011                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2012                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2013                                 $m )
2014                         )
2015                         {
2016                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2017                                         $result = false;
2018                                         return $result;
2019                                 }
2020                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2021                                 $result = true;
2022                         }
2023                 }
2024         }
2025         return $result;
2026 }
2027
2028 /**
2029  * Obtain the offset and limit values from the request string;
2030  * used in special pages
2031  *
2032  * @param int $deflimit default limit if none supplied
2033  * @param string $optionname Name of a user preference to check against
2034  * @return array
2035  *
2036  */
2037 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2038         global $wgRequest;
2039         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2040 }
2041
2042 /**
2043  * Escapes the given text so that it may be output using addWikiText()
2044  * without any linking, formatting, etc. making its way through. This
2045  * is achieved by substituting certain characters with HTML entities.
2046  * As required by the callers, "<nowiki>" is not used.
2047  *
2048  * @param string $text text to be escaped
2049  * @return String
2050  */
2051 function wfEscapeWikiText( $text ) {
2052         $text = strtr( "\n$text", array(
2053                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2054                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2055                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2056                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2057                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2058                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2059         ) );
2060         return substr( $text, 1 );
2061 }
2062
2063 /**
2064  * Get the current unix timestamp with microseconds.  Useful for profiling
2065  * @return Float
2066  */
2067 function wfTime() {
2068         return microtime( true );
2069 }
2070
2071 /**
2072  * Sets dest to source and returns the original value of dest
2073  * If source is NULL, it just returns the value, it doesn't set the variable
2074  * If force is true, it will set the value even if source is NULL
2075  *
2076  * @param $dest Mixed
2077  * @param $source Mixed
2078  * @param $force Bool
2079  * @return Mixed
2080  */
2081 function wfSetVar( &$dest, $source, $force = false ) {
2082         $temp = $dest;
2083         if ( !is_null( $source ) || $force ) {
2084                 $dest = $source;
2085         }
2086         return $temp;
2087 }
2088
2089 /**
2090  * As for wfSetVar except setting a bit
2091  *
2092  * @param $dest Int
2093  * @param $bit Int
2094  * @param $state Bool
2095  *
2096  * @return bool
2097  */
2098 function wfSetBit( &$dest, $bit, $state = true ) {
2099         $temp = (bool)( $dest & $bit );
2100         if ( !is_null( $state ) ) {
2101                 if ( $state ) {
2102                         $dest |= $bit;
2103                 } else {
2104                         $dest &= ~$bit;
2105                 }
2106         }
2107         return $temp;
2108 }
2109
2110 /**
2111  * A wrapper around the PHP function var_export().
2112  * Either print it or add it to the regular output ($wgOut).
2113  *
2114  * @param $var mixed A PHP variable to dump.
2115  */
2116 function wfVarDump( $var ) {
2117         global $wgOut;
2118         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2119         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2120                 print $s;
2121         } else {
2122                 $wgOut->addHTML( $s );
2123         }
2124 }
2125
2126 /**
2127  * Provide a simple HTTP error.
2128  *
2129  * @param $code Int|String
2130  * @param $label String
2131  * @param $desc String
2132  */
2133 function wfHttpError( $code, $label, $desc ) {
2134         global $wgOut;
2135         $wgOut->disable();
2136         header( "HTTP/1.0 $code $label" );
2137         header( "Status: $code $label" );
2138         $wgOut->sendCacheControl();
2139
2140         header( 'Content-type: text/html; charset=utf-8' );
2141         print "<!doctype html>" .
2142                 '<html><head><title>' .
2143                 htmlspecialchars( $label ) .
2144                 '</title></head><body><h1>' .
2145                 htmlspecialchars( $label ) .
2146                 '</h1><p>' .
2147                 nl2br( htmlspecialchars( $desc ) ) .
2148                 "</p></body></html>\n";
2149 }
2150
2151 /**
2152  * Clear away any user-level output buffers, discarding contents.
2153  *
2154  * Suitable for 'starting afresh', for instance when streaming
2155  * relatively large amounts of data without buffering, or wanting to
2156  * output image files without ob_gzhandler's compression.
2157  *
2158  * The optional $resetGzipEncoding parameter controls suppression of
2159  * the Content-Encoding header sent by ob_gzhandler; by default it
2160  * is left. See comments for wfClearOutputBuffers() for why it would
2161  * be used.
2162  *
2163  * Note that some PHP configuration options may add output buffer
2164  * layers which cannot be removed; these are left in place.
2165  *
2166  * @param $resetGzipEncoding Bool
2167  */
2168 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2169         if ( $resetGzipEncoding ) {
2170                 // Suppress Content-Encoding and Content-Length
2171                 // headers from 1.10+s wfOutputHandler
2172                 global $wgDisableOutputCompression;
2173                 $wgDisableOutputCompression = true;
2174         }
2175         while ( $status = ob_get_status() ) {
2176                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2177                         // Probably from zlib.output_compression or other
2178                         // PHP-internal setting which can't be removed.
2179                         //
2180                         // Give up, and hope the result doesn't break
2181                         // output behavior.
2182                         break;
2183                 }
2184                 if ( !ob_end_clean() ) {
2185                         // Could not remove output buffer handler; abort now
2186                         // to avoid getting in some kind of infinite loop.
2187                         break;
2188                 }
2189                 if ( $resetGzipEncoding ) {
2190                         if ( $status['name'] == 'ob_gzhandler' ) {
2191                                 // Reset the 'Content-Encoding' field set by this handler
2192                                 // so we can start fresh.
2193                                 header_remove( 'Content-Encoding' );
2194                                 break;
2195                         }
2196                 }
2197         }
2198 }
2199
2200 /**
2201  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2202  *
2203  * Clear away output buffers, but keep the Content-Encoding header
2204  * produced by ob_gzhandler, if any.
2205  *
2206  * This should be used for HTTP 304 responses, where you need to
2207  * preserve the Content-Encoding header of the real result, but
2208  * also need to suppress the output of ob_gzhandler to keep to spec
2209  * and avoid breaking Firefox in rare cases where the headers and
2210  * body are broken over two packets.
2211  */
2212 function wfClearOutputBuffers() {
2213         wfResetOutputBuffers( false );
2214 }
2215
2216 /**
2217  * Converts an Accept-* header into an array mapping string values to quality
2218  * factors
2219  *
2220  * @param $accept String
2221  * @param string $def default
2222  * @return Array
2223  */
2224 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2225         # No arg means accept anything (per HTTP spec)
2226         if ( !$accept ) {
2227                 return array( $def => 1.0 );
2228         }
2229
2230         $prefs = array();
2231
2232         $parts = explode( ',', $accept );
2233
2234         foreach ( $parts as $part ) {
2235                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2236                 $values = explode( ';', trim( $part ) );
2237                 $match = array();
2238                 if ( count( $values ) == 1 ) {
2239                         $prefs[$values[0]] = 1.0;
2240                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2241                         $prefs[$values[0]] = floatval( $match[1] );
2242                 }
2243         }
2244
2245         return $prefs;
2246 }
2247
2248 /**
2249  * Checks if a given MIME type matches any of the keys in the given
2250  * array. Basic wildcards are accepted in the array keys.
2251  *
2252  * Returns the matching MIME type (or wildcard) if a match, otherwise
2253  * NULL if no match.
2254  *
2255  * @param $type String
2256  * @param $avail Array
2257  * @return string
2258  * @private
2259  */
2260 function mimeTypeMatch( $type, $avail ) {
2261         if ( array_key_exists( $type, $avail ) ) {
2262                 return $type;
2263         } else {
2264                 $parts = explode( '/', $type );
2265                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2266                         return $parts[0] . '/*';
2267                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2268                         return '*/*';
2269                 } else {
2270                         return null;
2271                 }
2272         }
2273 }
2274
2275 /**
2276  * Returns the 'best' match between a client's requested internet media types
2277  * and the server's list of available types. Each list should be an associative
2278  * array of type to preference (preference is a float between 0.0 and 1.0).
2279  * Wildcards in the types are acceptable.
2280  *
2281  * @param array $cprefs client's acceptable type list
2282  * @param array $sprefs server's offered types
2283  * @return string
2284  *
2285  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2286  * XXX: generalize to negotiate other stuff
2287  */
2288 function wfNegotiateType( $cprefs, $sprefs ) {
2289         $combine = array();
2290
2291         foreach ( array_keys( $sprefs ) as $type ) {
2292                 $parts = explode( '/', $type );
2293                 if ( $parts[1] != '*' ) {
2294                         $ckey = mimeTypeMatch( $type, $cprefs );
2295                         if ( $ckey ) {
2296                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2297                         }
2298                 }
2299         }
2300
2301         foreach ( array_keys( $cprefs ) as $type ) {
2302                 $parts = explode( '/', $type );
2303                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2304                         $skey = mimeTypeMatch( $type, $sprefs );
2305                         if ( $skey ) {
2306                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2307                         }
2308                 }
2309         }
2310
2311         $bestq = 0;
2312         $besttype = null;
2313
2314         foreach ( array_keys( $combine ) as $type ) {
2315                 if ( $combine[$type] > $bestq ) {
2316                         $besttype = $type;
2317                         $bestq = $combine[$type];
2318                 }
2319         }
2320
2321         return $besttype;
2322 }
2323
2324 /**
2325  * Reference-counted warning suppression
2326  *
2327  * @param $end Bool
2328  */
2329 function wfSuppressWarnings( $end = false ) {
2330         static $suppressCount = 0;
2331         static $originalLevel = false;
2332
2333         if ( $end ) {
2334                 if ( $suppressCount ) {
2335                         --$suppressCount;
2336                         if ( !$suppressCount ) {
2337                                 error_reporting( $originalLevel );
2338                         }
2339                 }
2340         } else {
2341                 if ( !$suppressCount ) {
2342                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2343                 }
2344                 ++$suppressCount;
2345         }
2346 }
2347
2348 /**
2349  * Restore error level to previous value
2350  */
2351 function wfRestoreWarnings() {
2352         wfSuppressWarnings( true );
2353 }
2354
2355 # Autodetect, convert and provide timestamps of various types
2356
2357 /**
2358  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2359  */
2360 define( 'TS_UNIX', 0 );
2361
2362 /**
2363  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2364  */
2365 define( 'TS_MW', 1 );
2366
2367 /**
2368  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2369  */
2370 define( 'TS_DB', 2 );
2371
2372 /**
2373  * RFC 2822 format, for E-mail and HTTP headers
2374  */
2375 define( 'TS_RFC2822', 3 );
2376
2377 /**
2378  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2379  *
2380  * This is used by Special:Export
2381  */
2382 define( 'TS_ISO_8601', 4 );
2383
2384 /**
2385  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2386  *
2387  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2388  *       DateTime tag and page 36 for the DateTimeOriginal and
2389  *       DateTimeDigitized tags.
2390  */
2391 define( 'TS_EXIF', 5 );
2392
2393 /**
2394  * Oracle format time.
2395  */
2396 define( 'TS_ORACLE', 6 );
2397
2398 /**
2399  * Postgres format time.
2400  */
2401 define( 'TS_POSTGRES', 7 );
2402
2403 /**
2404  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2405  */
2406 define( 'TS_ISO_8601_BASIC', 9 );
2407
2408 /**
2409  * Get a timestamp string in one of various formats
2410  *
2411  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2412  *                    function will autodetect which format is supplied and act
2413  *                    accordingly.
2414  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2415  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2416  */
2417 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2418         try {
2419                 $timestamp = new MWTimestamp( $ts );
2420                 return $timestamp->getTimestamp( $outputtype );
2421         } catch( TimestampException $e ) {
2422                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2423                 return false;
2424         }
2425 }
2426
2427 /**
2428  * Return a formatted timestamp, or null if input is null.
2429  * For dealing with nullable timestamp columns in the database.
2430  *
2431  * @param $outputtype Integer
2432  * @param $ts String
2433  * @return String
2434  */
2435 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2436         if ( is_null( $ts ) ) {
2437                 return null;
2438         } else {
2439                 return wfTimestamp( $outputtype, $ts );
2440         }
2441 }
2442
2443 /**
2444  * Convenience function; returns MediaWiki timestamp for the present time.
2445  *
2446  * @return string
2447  */
2448 function wfTimestampNow() {
2449         # return NOW
2450         return wfTimestamp( TS_MW, time() );
2451 }
2452
2453 /**
2454  * Check if the operating system is Windows
2455  *
2456  * @return Bool: true if it's Windows, False otherwise.
2457  */
2458 function wfIsWindows() {
2459         static $isWindows = null;
2460         if ( $isWindows === null ) {
2461                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2462         }
2463         return $isWindows;
2464 }
2465
2466 /**
2467  * Check if we are running under HipHop
2468  *
2469  * @return Bool
2470  */
2471 function wfIsHipHop() {
2472         return function_exists( 'hphp_thread_set_warmup_enabled' );
2473 }
2474
2475 /**
2476  * Swap two variables
2477  *
2478  * @param $x Mixed
2479  * @param $y Mixed
2480  */
2481 function swap( &$x, &$y ) {
2482         $z = $x;
2483         $x = $y;
2484         $y = $z;
2485 }
2486
2487 /**
2488  * Tries to get the system directory for temporary files. First
2489  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2490  * environment variables are then checked in sequence, and if none are
2491  * set try sys_get_temp_dir().
2492  *
2493  * NOTE: When possible, use instead the tmpfile() function to create
2494  * temporary files to avoid race conditions on file creation, etc.
2495  *
2496  * @return String
2497  */
2498 function wfTempDir() {
2499         global $wgTmpDirectory;
2500
2501         if ( $wgTmpDirectory !== false ) {
2502                 return $wgTmpDirectory;
2503         }
2504
2505         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2506
2507         foreach ( $tmpDir as $tmp ) {
2508                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2509                         return $tmp;
2510                 }
2511         }
2512         return sys_get_temp_dir();
2513 }
2514
2515 /**
2516  * Make directory, and make all parent directories if they don't exist
2517  *
2518  * @param string $dir full path to directory to create
2519  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2520  * @param string $caller optional caller param for debugging.
2521  * @throws MWException
2522  * @return bool
2523  */
2524 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2525         global $wgDirectoryMode;
2526
2527         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2528                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2529         }
2530
2531         if ( !is_null( $caller ) ) {
2532                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2533         }
2534
2535         if ( strval( $dir ) === '' || file_exists( $dir ) ) {
2536                 return true;
2537         }
2538
2539         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2540
2541         if ( is_null( $mode ) ) {
2542                 $mode = $wgDirectoryMode;
2543         }
2544
2545         // Turn off the normal warning, we're doing our own below
2546         wfSuppressWarnings();
2547         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2548         wfRestoreWarnings();
2549
2550         if ( !$ok ) {
2551                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2552                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2553         }
2554         return $ok;
2555 }
2556
2557 /**
2558  * Remove a directory and all its content.
2559  * Does not hide error.
2560  */
2561 function wfRecursiveRemoveDir( $dir ) {
2562         wfDebug( __FUNCTION__ . "( $dir )\n" );
2563         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2564         if ( is_dir( $dir ) ) {
2565                 $objects = scandir( $dir );
2566                 foreach ( $objects as $object ) {
2567                         if ( $object != "." && $object != ".." ) {
2568                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2569                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2570                                 } else {
2571                                         unlink( $dir . '/' . $object );
2572                                 }
2573                         }
2574                 }
2575                 reset( $objects );
2576                 rmdir( $dir );
2577         }
2578 }
2579
2580 /**
2581  * @param $nr Mixed: the number to format
2582  * @param $acc Integer: the number of digits after the decimal point, default 2
2583  * @param $round Boolean: whether or not to round the value, default true
2584  * @return float
2585  */
2586 function wfPercent( $nr, $acc = 2, $round = true ) {
2587         $ret = sprintf( "%.${acc}f", $nr );
2588         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2589 }
2590
2591 /**
2592  * Find out whether or not a mixed variable exists in a string
2593  *
2594  * @deprecated Just use str(i)pos
2595  * @param $needle String
2596  * @param $str String
2597  * @param $insensitive Boolean
2598  * @return Boolean
2599  */
2600 function in_string( $needle, $str, $insensitive = false ) {
2601         wfDeprecated( __METHOD__, '1.21' );
2602         $func = 'strpos';
2603         if ( $insensitive ) {
2604                 $func = 'stripos';
2605         }
2606
2607         return $func( $str, $needle ) !== false;
2608 }
2609
2610 /**
2611  * Safety wrapper around ini_get() for boolean settings.
2612  * The values returned from ini_get() are pre-normalized for settings
2613  * set via php.ini or php_flag/php_admin_flag... but *not*
2614  * for those set via php_value/php_admin_value.
2615  *
2616  * It's fairly common for people to use php_value instead of php_flag,
2617  * which can leave you with an 'off' setting giving a false positive
2618  * for code that just takes the ini_get() return value as a boolean.
2619  *
2620  * To make things extra interesting, setting via php_value accepts
2621  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2622  * Unrecognized values go false... again opposite PHP's own coercion
2623  * from string to bool.
2624  *
2625  * Luckily, 'properly' set settings will always come back as '0' or '1',
2626  * so we only have to worry about them and the 'improper' settings.
2627  *
2628  * I frickin' hate PHP... :P
2629  *
2630  * @param $setting String
2631  * @return Bool
2632  */
2633 function wfIniGetBool( $setting ) {
2634         $val = ini_get( $setting );
2635         // 'on' and 'true' can't have whitespace around them, but '1' can.
2636         return strtolower( $val ) == 'on'
2637                 || strtolower( $val ) == 'true'
2638                 || strtolower( $val ) == 'yes'
2639                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2640 }
2641
2642 /**
2643  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2644  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2645  *
2646  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2647  *                          should be omitted
2648  * @param string $fileName Name of the library, if not $extension.suffix
2649  * @return Bool - Whether or not the extension is loaded
2650  */
2651 function wfDl( $extension, $fileName = null ) {
2652         if ( extension_loaded( $extension ) ) {
2653                 return true;
2654         }
2655
2656         $canDl = false;
2657         if ( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2658                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2659                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2660         }
2661
2662         if ( $canDl ) {
2663                 $fileName = $fileName ? $fileName : $extension;
2664                 if ( wfIsWindows() ) {
2665                         $fileName = 'php_' . $fileName;
2666                 }
2667                 wfSuppressWarnings();
2668                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2669                 wfRestoreWarnings();
2670         }
2671         return extension_loaded( $extension );
2672 }
2673
2674 /**
2675  * Windows-compatible version of escapeshellarg()
2676  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2677  * function puts single quotes in regardless of OS.
2678  *
2679  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2680  * earlier distro releases of PHP)
2681  *
2682  * @param varargs
2683  * @return String
2684  */
2685 function wfEscapeShellArg() {
2686         wfInitShellLocale();
2687
2688         $args = func_get_args();
2689         $first = true;
2690         $retVal = '';
2691         foreach ( $args as $arg ) {
2692                 if ( !$first ) {
2693                         $retVal .= ' ';
2694                 } else {
2695                         $first = false;
2696                 }
2697
2698                 if ( wfIsWindows() ) {
2699                         // Escaping for an MSVC-style command line parser and CMD.EXE
2700                         // Refs:
2701                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2702                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2703                         //  * Bug #13518
2704                         //  * CR r63214
2705                         // Double the backslashes before any double quotes. Escape the double quotes.
2706                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2707                         $arg = '';
2708                         $iteration = 0;
2709                         foreach ( $tokens as $token ) {
2710                                 if ( $iteration % 2 == 1 ) {
2711                                         // Delimiter, a double quote preceded by zero or more slashes
2712                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2713                                 } elseif ( $iteration % 4 == 2 ) {
2714                                         // ^ in $token will be outside quotes, need to be escaped
2715                                         $arg .= str_replace( '^', '^^', $token );
2716                                 } else { // $iteration % 4 == 0
2717                                         // ^ in $token will appear inside double quotes, so leave as is
2718                                         $arg .= $token;
2719                                 }
2720                                 $iteration++;
2721                         }
2722                         // Double the backslashes before the end of the string, because
2723                         // we will soon add a quote
2724                         $m = array();
2725                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2726                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2727                         }
2728
2729                         // Add surrounding quotes
2730                         $retVal .= '"' . $arg . '"';
2731                 } else {
2732                         $retVal .= escapeshellarg( $arg );
2733                 }
2734         }
2735         return $retVal;
2736 }
2737
2738 /**
2739  * Execute a shell command, with time and memory limits mirrored from the PHP
2740  * configuration if supported.
2741  * @param string $cmd Command line, properly escaped for shell.
2742  * @param &$retval null|Mixed optional, will receive the program's exit code.
2743  *                 (non-zero is usually failure)
2744  * @param array $environ optional environment variables which should be
2745  *                 added to the executed command environment.
2746  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2747  *                 this overwrites the global wgShellMax* limits.
2748  * @return string collected stdout as a string (trailing newlines stripped)
2749  */
2750 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2751         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2752                 $wgMaxShellWallClockTime, $wgShellCgroup;
2753
2754         static $disabled;
2755         if ( is_null( $disabled ) ) {
2756                 $disabled = false;
2757                 if ( wfIniGetBool( 'safe_mode' ) ) {
2758                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2759                         $disabled = 'safemode';
2760                 } else {
2761                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2762                         $functions = array_map( 'trim', $functions );
2763                         $functions = array_map( 'strtolower', $functions );
2764                         if ( in_array( 'passthru', $functions ) ) {
2765                                 wfDebug( "passthru is in disabled_functions\n" );
2766                                 $disabled = 'passthru';
2767                         }
2768                 }
2769         }
2770         if ( $disabled ) {
2771                 $retval = 1;
2772                 return $disabled == 'safemode' ?
2773                         'Unable to run external programs in safe mode.' :
2774                         'Unable to run external programs, passthru() is disabled.';
2775         }
2776
2777         wfInitShellLocale();
2778
2779         $envcmd = '';
2780         foreach ( $environ as $k => $v ) {
2781                 if ( wfIsWindows() ) {
2782                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2783                          * appear in the environment variable, so we must use carat escaping as documented in
2784                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2785                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2786                          * are listed there but doesn't appear to need it.
2787                          */
2788                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2789                 } else {
2790                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2791                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2792                          */
2793                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2794                 }
2795         }
2796         $cmd = $envcmd . $cmd;
2797
2798         if ( php_uname( 's' ) == 'Linux' ) {
2799                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2800                 if ( isset( $limits['walltime'] ) ) {
2801                         $wallTime = intval( $limits['walltime'] );
2802                 } elseif ( isset( $limits['time'] ) ) {
2803                         $wallTime = $time;
2804                 } else {
2805                         $wallTime = intval( $wgMaxShellWallClockTime );
2806                 }
2807                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2808                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2809
2810                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2811                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2812                                 escapeshellarg( $cmd ) . ' ' .
2813                                 escapeshellarg(
2814                                         "MW_CPU_LIMIT=$time; " .
2815                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2816                                         "MW_MEM_LIMIT=$mem; " .
2817                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2818                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2819                                 );
2820                 }
2821         }
2822         wfDebug( "wfShellExec: $cmd\n" );
2823
2824         $retval = 1; // error by default?
2825         ob_start();
2826         passthru( $cmd, $retval );
2827         $output = ob_get_contents();
2828         ob_end_clean();
2829
2830         if ( $retval == 127 ) {
2831                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2832         }
2833         return $output;
2834 }
2835
2836 /**
2837  * Workaround for http://bugs.php.net/bug.php?id=45132
2838  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2839  */
2840 function wfInitShellLocale() {
2841         static $done = false;
2842         if ( $done ) {
2843                 return;
2844         }
2845         $done = true;
2846         global $wgShellLocale;
2847         if ( !wfIniGetBool( 'safe_mode' ) ) {
2848                 putenv( "LC_CTYPE=$wgShellLocale" );
2849                 setlocale( LC_CTYPE, $wgShellLocale );
2850         }
2851 }
2852
2853 /**
2854  * Alias to wfShellWikiCmd()
2855  * @see wfShellWikiCmd()
2856  */
2857 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2858         return wfShellWikiCmd( $script, $parameters, $options );
2859 }
2860
2861 /**
2862  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2863  * Note that $parameters should be a flat array and an option with an argument
2864  * should consist of two consecutive items in the array (do not use "--option value").
2865  * @param string $script MediaWiki cli script path
2866  * @param array $parameters Arguments and options to the script
2867  * @param array $options Associative array of options:
2868  *              'php': The path to the php executable
2869  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2870  * @return Array
2871  */
2872 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2873         global $wgPhpCli;
2874         // Give site config file a chance to run the script in a wrapper.
2875         // The caller may likely want to call wfBasename() on $script.
2876         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2877         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2878         if ( isset( $options['wrapper'] ) ) {
2879                 $cmd[] = $options['wrapper'];
2880         }
2881         $cmd[] = $script;
2882         // Escape each parameter for shell
2883         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2884 }
2885
2886 /**
2887  * wfMerge attempts to merge differences between three texts.
2888  * Returns true for a clean merge and false for failure or a conflict.
2889  *
2890  * @param $old String
2891  * @param $mine String
2892  * @param $yours String
2893  * @param $result String
2894  * @return Bool
2895  */
2896 function wfMerge( $old, $mine, $yours, &$result ) {
2897         global $wgDiff3;
2898
2899         # This check may also protect against code injection in
2900         # case of broken installations.
2901         wfSuppressWarnings();
2902         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2903         wfRestoreWarnings();
2904
2905         if ( !$haveDiff3 ) {
2906                 wfDebug( "diff3 not found\n" );
2907                 return false;
2908         }
2909
2910         # Make temporary files
2911         $td = wfTempDir();
2912         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2913         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2914         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2915
2916         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2917         #       a newline character. To avoid this, we normalize the trailing whitespace before
2918         #       creating the diff.
2919
2920         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2921         fclose( $oldtextFile );
2922         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2923         fclose( $mytextFile );
2924         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2925         fclose( $yourtextFile );
2926
2927         # Check for a conflict
2928         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2929                 wfEscapeShellArg( $mytextName ) . ' ' .
2930                 wfEscapeShellArg( $oldtextName ) . ' ' .
2931                 wfEscapeShellArg( $yourtextName );
2932         $handle = popen( $cmd, 'r' );
2933
2934         if ( fgets( $handle, 1024 ) ) {
2935                 $conflict = true;
2936         } else {
2937                 $conflict = false;
2938         }
2939         pclose( $handle );
2940
2941         # Merge differences
2942         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2943                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2944         $handle = popen( $cmd, 'r' );
2945         $result = '';
2946         do {
2947                 $data = fread( $handle, 8192 );
2948                 if ( strlen( $data ) == 0 ) {
2949                         break;
2950                 }
2951                 $result .= $data;
2952         } while ( true );
2953         pclose( $handle );
2954         unlink( $mytextName );
2955         unlink( $oldtextName );
2956         unlink( $yourtextName );
2957
2958         if ( $result === '' && $old !== '' && !$conflict ) {
2959                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2960                 $conflict = true;
2961         }
2962         return !$conflict;
2963 }
2964
2965 /**
2966  * Returns unified plain-text diff of two texts.
2967  * Useful for machine processing of diffs.
2968  *
2969  * @param string $before the text before the changes.
2970  * @param string $after the text after the changes.
2971  * @param string $params command-line options for the diff command.
2972  * @return String: unified diff of $before and $after
2973  */
2974 function wfDiff( $before, $after, $params = '-u' ) {
2975         if ( $before == $after ) {
2976                 return '';
2977         }
2978
2979         global $wgDiff;
2980         wfSuppressWarnings();
2981         $haveDiff = $wgDiff && file_exists( $wgDiff );
2982         wfRestoreWarnings();
2983
2984         # This check may also protect against code injection in
2985         # case of broken installations.
2986         if ( !$haveDiff ) {
2987                 wfDebug( "diff executable not found\n" );
2988                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2989                 $format = new UnifiedDiffFormatter();
2990                 return $format->format( $diffs );
2991         }
2992
2993         # Make temporary files
2994         $td = wfTempDir();
2995         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2996         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2997
2998         fwrite( $oldtextFile, $before );
2999         fclose( $oldtextFile );
3000         fwrite( $newtextFile, $after );
3001         fclose( $newtextFile );
3002
3003         // Get the diff of the two files
3004         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3005
3006         $h = popen( $cmd, 'r' );
3007
3008         $diff = '';
3009
3010         do {
3011                 $data = fread( $h, 8192 );
3012                 if ( strlen( $data ) == 0 ) {
3013                         break;
3014                 }
3015                 $diff .= $data;
3016         } while ( true );
3017
3018         // Clean up
3019         pclose( $h );
3020         unlink( $oldtextName );
3021         unlink( $newtextName );
3022
3023         // Kill the --- and +++ lines. They're not useful.
3024         $diff_lines = explode( "\n", $diff );
3025         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3026                 unset( $diff_lines[0] );
3027         }
3028         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3029                 unset( $diff_lines[1] );
3030         }
3031
3032         $diff = implode( "\n", $diff_lines );
3033
3034         return $diff;
3035 }
3036
3037 /**
3038  * This function works like "use VERSION" in Perl, the program will die with a
3039  * backtrace if the current version of PHP is less than the version provided
3040  *
3041  * This is useful for extensions which due to their nature are not kept in sync
3042  * with releases, and might depend on other versions of PHP than the main code
3043  *
3044  * Note: PHP might die due to parsing errors in some cases before it ever
3045  *       manages to call this function, such is life
3046  *
3047  * @see perldoc -f use
3048  *
3049  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3050  *                 a float
3051  * @throws MWException
3052  */
3053 function wfUsePHP( $req_ver ) {
3054         $php_ver = PHP_VERSION;
3055
3056         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3057                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3058         }
3059 }
3060
3061 /**
3062  * This function works like "use VERSION" in Perl except it checks the version
3063  * of MediaWiki, the program will die with a backtrace if the current version
3064  * of MediaWiki is less than the version provided.
3065  *
3066  * This is useful for extensions which due to their nature are not kept in sync
3067  * with releases
3068  *
3069  * @see perldoc -f use
3070  *
3071  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3072  *                 a float
3073  * @throws MWException
3074  */
3075 function wfUseMW( $req_ver ) {
3076         global $wgVersion;
3077
3078         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3079                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3080         }
3081 }
3082
3083 /**
3084  * Return the final portion of a pathname.
3085  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3086  * http://bugs.php.net/bug.php?id=33898
3087  *
3088  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3089  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3090  *
3091  * @param $path String
3092  * @param string $suffix to remove if present
3093  * @return String
3094  */
3095 function wfBaseName( $path, $suffix = '' ) {
3096         $encSuffix = ( $suffix == '' )
3097                 ? ''
3098                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3099         $matches = array();
3100         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3101                 return $matches[1];
3102         } else {
3103                 return '';
3104         }
3105 }
3106
3107 /**
3108  * Generate a relative path name to the given file.
3109  * May explode on non-matching case-insensitive paths,
3110  * funky symlinks, etc.
3111  *
3112  * @param string $path absolute destination path including target filename
3113  * @param string $from Absolute source path, directory only
3114  * @return String
3115  */
3116 function wfRelativePath( $path, $from ) {
3117         // Normalize mixed input on Windows...
3118         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3119         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3120
3121         // Trim trailing slashes -- fix for drive root
3122         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3123         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3124
3125         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3126         $against = explode( DIRECTORY_SEPARATOR, $from );
3127
3128         if ( $pieces[0] !== $against[0] ) {
3129                 // Non-matching Windows drive letters?
3130                 // Return a full path.
3131                 return $path;
3132         }
3133
3134         // Trim off common prefix
3135         while ( count( $pieces ) && count( $against )
3136                 && $pieces[0] == $against[0] ) {
3137                 array_shift( $pieces );
3138                 array_shift( $against );
3139         }
3140
3141         // relative dots to bump us to the parent
3142         while ( count( $against ) ) {
3143                 array_unshift( $pieces, '..' );
3144                 array_shift( $against );
3145         }
3146
3147         array_push( $pieces, wfBaseName( $path ) );
3148
3149         return implode( DIRECTORY_SEPARATOR, $pieces );
3150 }
3151
3152 /**
3153  * Do any deferred updates and clear the list
3154  *
3155  * @deprecated since 1.19
3156  * @see DeferredUpdates::doUpdate()
3157  * @param $commit string
3158  */
3159 function wfDoUpdates( $commit = '' ) {
3160         wfDeprecated( __METHOD__, '1.19' );
3161         DeferredUpdates::doUpdates( $commit );
3162 }
3163
3164 /**
3165  * Convert an arbitrarily-long digit string from one numeric base
3166  * to another, optionally zero-padding to a minimum column width.
3167  *
3168  * Supports base 2 through 36; digit values 10-36 are represented
3169  * as lowercase letters a-z. Input is case-insensitive.
3170  *
3171  * @param string $input Input number
3172  * @param int $sourceBase Base of the input number
3173  * @param int $destBase Desired base of the output
3174  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3175  * @param bool $lowercase Whether to output in lowercase or uppercase
3176  * @param string $engine Either "gmp", "bcmath", or "php"
3177  * @return string|bool The output number as a string, or false on error
3178  */
3179 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3180         $input = (string)$input;
3181         if (
3182                 $sourceBase < 2 ||
3183                 $sourceBase > 36 ||
3184                 $destBase < 2 ||
3185                 $destBase > 36 ||
3186                 $sourceBase != (int) $sourceBase ||
3187                 $destBase != (int) $destBase ||
3188                 $pad != (int) $pad ||
3189                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3190         ) {
3191                 return false;
3192         }
3193
3194         static $baseChars = array(
3195                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3196                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3197                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3198                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3199                 34 => 'y', 35 => 'z',
3200
3201                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3202                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3203                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3204                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3205                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3206                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3207         );
3208
3209         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3210                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3211         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3212                 $decimal = '0';
3213                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3214                         $decimal = bcmul( $decimal, $sourceBase );
3215                         $decimal = bcadd( $decimal, $baseChars[$char] );
3216                 }
3217
3218                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3219                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3220                 }
3221
3222                 $result = strrev( $result );
3223         } else {
3224                 $inDigits = array();
3225                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3226                         $inDigits[] = $baseChars[$char];
3227                 }
3228
3229                 // Iterate over the input, modulo-ing out an output digit
3230                 // at a time until input is gone.
3231                 $result = '';
3232                 while ( $inDigits ) {
3233                         $work = 0;
3234                         $workDigits = array();
3235
3236                         // Long division...
3237                         foreach ( $inDigits as $digit ) {
3238                                 $work *= $sourceBase;
3239                                 $work += $digit;
3240
3241                                 if ( $workDigits || $work >= $destBase ) {
3242                                         $workDigits[] = (int) ( $work / $destBase );
3243                                 }
3244                                 $work %= $destBase;
3245                         }
3246
3247                         // All that division leaves us with a remainder,
3248                         // which is conveniently our next output digit.
3249                         $result .= $baseChars[$work];
3250
3251                         // And we continue!
3252                         $inDigits = $workDigits;
3253                 }
3254
3255                 $result = strrev( $result );
3256         }
3257
3258         if ( !$lowercase ) {
3259                 $result = strtoupper( $result );
3260         }
3261
3262         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3263 }
3264
3265 /**
3266  * Create an object with a given name and an array of construct parameters
3267  *
3268  * @param $name String
3269  * @param array $p parameters
3270  * @return object
3271  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3272  */
3273 function wfCreateObject( $name, $p ) {
3274         wfDeprecated( __FUNCTION__, '1.18' );
3275         return MWFunction::newObj( $name, $p );
3276 }
3277
3278 /**
3279  * @return bool
3280  */
3281 function wfHttpOnlySafe() {
3282         global $wgHttpOnlyBlacklist;
3283
3284         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3285                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3286                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3287                                 return false;
3288                         }
3289                 }
3290         }
3291
3292         return true;
3293 }
3294
3295 /**
3296  * Check if there is sufficient entropy in php's built-in session generation
3297  * @return bool true = there is sufficient entropy
3298  */
3299 function wfCheckEntropy() {
3300         return (
3301                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3302                         || ini_get( 'session.entropy_file' )
3303                 )
3304                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3305 }
3306
3307 /**
3308  * Override session_id before session startup if php's built-in
3309  * session generation code is not secure.
3310  */
3311 function wfFixSessionID() {
3312         // If the cookie or session id is already set we already have a session and should abort
3313         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3314                 return;
3315         }
3316
3317         // PHP's built-in session entropy is enabled if:
3318         // - entropy_file is set or you're on Windows with php 5.3.3+
3319         // - AND entropy_length is > 0
3320         // We treat it as disabled if it doesn't have an entropy length of at least 32
3321         $entropyEnabled = wfCheckEntropy();
3322
3323         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3324         if ( !$entropyEnabled ) {
3325                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3326                 session_id( MWCryptRand::generateHex( 32 ) );
3327         }
3328 }
3329
3330 /**
3331  * Initialise php session
3332  *
3333  * @param $sessionId Bool
3334  */
3335 function wfSetupSession( $sessionId = false ) {
3336         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3337                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3338         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3339                 ObjectCacheSessionHandler::install();
3340         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3341                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3342                 # hasn't already been set to the desired value (that causes errors)
3343                 ini_set( 'session.save_handler', $wgSessionHandler );
3344         }
3345         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3346         wfDebugLog( 'cookie',
3347                 'session_set_cookie_params: "' . implode( '", "',
3348                         array(
3349                                 0,
3350                                 $wgCookiePath,
3351                                 $wgCookieDomain,
3352                                 $wgCookieSecure,
3353                                 $httpOnlySafe ) ) . '"' );
3354         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3355         session_cache_limiter( 'private, must-revalidate' );
3356         if ( $sessionId ) {
3357                 session_id( $sessionId );
3358         } else {
3359                 wfFixSessionID();
3360         }
3361         wfSuppressWarnings();
3362         session_start();
3363         wfRestoreWarnings();
3364 }
3365
3366 /**
3367  * Get an object from the precompiled serialized directory
3368  *
3369  * @param $name String
3370  * @return Mixed: the variable on success, false on failure
3371  */
3372 function wfGetPrecompiledData( $name ) {
3373         global $IP;
3374
3375         $file = "$IP/serialized/$name";
3376         if ( file_exists( $file ) ) {
3377                 $blob = file_get_contents( $file );
3378                 if ( $blob ) {
3379                         return unserialize( $blob );
3380                 }
3381         }
3382         return false;
3383 }
3384
3385 /**
3386  * Get a cache key
3387  *
3388  * @param varargs
3389  * @return String
3390  */
3391 function wfMemcKey( /*... */ ) {
3392         global $wgCachePrefix;
3393         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3394         $args = func_get_args();
3395         $key = $prefix . ':' . implode( ':', $args );
3396         $key = str_replace( ' ', '_', $key );
3397         return $key;
3398 }
3399
3400 /**
3401  * Get a cache key for a foreign DB
3402  *
3403  * @param $db String
3404  * @param $prefix String
3405  * @param varargs String
3406  * @return String
3407  */
3408 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3409         $args = array_slice( func_get_args(), 2 );
3410         if ( $prefix ) {
3411                 $key = "$db-$prefix:" . implode( ':', $args );
3412         } else {
3413                 $key = $db . ':' . implode( ':', $args );
3414         }
3415         return $key;
3416 }
3417
3418 /**
3419  * Get an ASCII string identifying this wiki
3420  * This is used as a prefix in memcached keys
3421  *
3422  * @return String
3423  */
3424 function wfWikiID() {
3425         global $wgDBprefix, $wgDBname;
3426         if ( $wgDBprefix ) {
3427                 return "$wgDBname-$wgDBprefix";
3428         } else {
3429                 return $wgDBname;
3430         }
3431 }
3432
3433 /**
3434  * Split a wiki ID into DB name and table prefix
3435  *
3436  * @param $wiki String
3437  *
3438  * @return array
3439  */
3440 function wfSplitWikiID( $wiki ) {
3441         $bits = explode( '-', $wiki, 2 );
3442         if ( count( $bits ) < 2 ) {
3443                 $bits[] = '';
3444         }
3445         return $bits;
3446 }
3447
3448 /**
3449  * Get a Database object.
3450  *
3451  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3452  *            master (for write queries), DB_SLAVE for potentially lagged read
3453  *            queries, or an integer >= 0 for a particular server.
3454  *
3455  * @param $groups Mixed: query groups. An array of group names that this query
3456  *                belongs to. May contain a single string if the query is only
3457  *                in one group.
3458  *
3459  * @param string $wiki the wiki ID, or false for the current wiki
3460  *
3461  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3462  * will always return the same object, unless the underlying connection or load
3463  * balancer is manually destroyed.
3464  *
3465  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3466  * updater to ensure that a proper database is being updated.
3467  *
3468  * @return DatabaseBase
3469  */
3470 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3471         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3472 }
3473
3474 /**
3475  * Get a load balancer object.
3476  *
3477  * @param string $wiki wiki ID, or false for the current wiki
3478  * @return LoadBalancer
3479  */
3480 function wfGetLB( $wiki = false ) {
3481         return wfGetLBFactory()->getMainLB( $wiki );
3482 }
3483
3484 /**
3485  * Get the load balancer factory object
3486  *
3487  * @return LBFactory
3488  */
3489 function &wfGetLBFactory() {
3490         return LBFactory::singleton();
3491 }
3492
3493 /**
3494  * Find a file.
3495  * Shortcut for RepoGroup::singleton()->findFile()
3496  *
3497  * @param string $title or Title object
3498  * @param array $options Associative array of options:
3499  *     time:           requested time for an archived image, or false for the
3500  *                     current version. An image object will be returned which was
3501  *                     created at the specified time.
3502  *
3503  *     ignoreRedirect: If true, do not follow file redirects
3504  *
3505  *     private:        If true, return restricted (deleted) files if the current
3506  *                     user is allowed to view them. Otherwise, such files will not
3507  *                     be found.
3508  *
3509  *     bypassCache:    If true, do not use the process-local cache of File objects
3510  *
3511  * @return File, or false if the file does not exist
3512  */
3513 function wfFindFile( $title, $options = array() ) {
3514         return RepoGroup::singleton()->findFile( $title, $options );
3515 }
3516
3517 /**
3518  * Get an object referring to a locally registered file.
3519  * Returns a valid placeholder object if the file does not exist.
3520  *
3521  * @param $title Title|String
3522  * @return LocalFile|null A File, or null if passed an invalid Title
3523  */
3524 function wfLocalFile( $title ) {
3525         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3526 }
3527
3528 /**
3529  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3530  * @deprecated since 1.19
3531  */
3532 function wfStreamFile( $fname, $headers = array() ) {
3533         wfDeprecated( __FUNCTION__, '1.19' );
3534         StreamFile::stream( $fname, $headers );
3535 }
3536
3537 /**
3538  * Should low-performance queries be disabled?
3539  *
3540  * @return Boolean
3541  * @codeCoverageIgnore
3542  */
3543 function wfQueriesMustScale() {
3544         global $wgMiserMode;
3545         return $wgMiserMode
3546                 || ( SiteStats::pages() > 100000
3547                 && SiteStats::edits() > 1000000
3548                 && SiteStats::users() > 10000 );
3549 }
3550
3551 /**
3552  * Get the path to a specified script file, respecting file
3553  * extensions; this is a wrapper around $wgScriptExtension etc.
3554  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3555  *
3556  * @param string $script script filename, sans extension
3557  * @return String
3558  */
3559 function wfScript( $script = 'index' ) {
3560         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3561         if ( $script === 'index' ) {
3562                 return $wgScript;
3563         } elseif ( $script === 'load' ) {
3564                 return $wgLoadScript;
3565         } else {
3566                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3567         }
3568 }
3569
3570 /**
3571  * Get the script URL.
3572  *
3573  * @return string script URL
3574  */
3575 function wfGetScriptUrl() {
3576         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3577                 #
3578                 # as it was called, minus the query string.
3579                 #
3580                 # Some sites use Apache rewrite rules to handle subdomains,
3581                 # and have PHP set up in a weird way that causes PHP_SELF
3582                 # to contain the rewritten URL instead of the one that the
3583                 # outside world sees.
3584                 #
3585                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3586                 # provides containing the "before" URL.
3587                 return $_SERVER['SCRIPT_NAME'];
3588         } else {
3589                 return $_SERVER['URL'];
3590         }
3591 }
3592
3593 /**
3594  * Convenience function converts boolean values into "true"
3595  * or "false" (string) values
3596  *
3597  * @param $value Boolean
3598  * @return String
3599  */
3600 function wfBoolToStr( $value ) {
3601         return $value ? 'true' : 'false';
3602 }
3603
3604 /**
3605  * Get a platform-independent path to the null file, e.g. /dev/null
3606  *
3607  * @return string
3608  */
3609 function wfGetNull() {
3610         return wfIsWindows()
3611                 ? 'NUL'
3612                 : '/dev/null';
3613 }
3614
3615 /**
3616  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3617  * and waiting for it to go down, this waits for the slaves to catch up to the
3618  * master position. Use this when updating very large numbers of rows, as
3619  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3620  * a no-op if there are no slaves.
3621  *
3622  * @param $maxLag Integer (deprecated)
3623  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3624  * @param $cluster string cluster name accepted by LBFactory
3625  */
3626 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3627         $lb = ( $cluster !== false )
3628                 ? wfGetLBFactory()->getExternalLB( $cluster )
3629                 : wfGetLB( $wiki );
3630         // bug 27975 - Don't try to wait for slaves if there are none
3631         // Prevents permission error when getting master position
3632         if ( $lb->getServerCount() > 1 ) {
3633                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3634                 $pos = $dbw->getMasterPos();
3635                 // The DBMS may not support getMasterPos() or the whole
3636                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3637                 if ( $pos !== false ) {
3638                         $lb->waitForAll( $pos );
3639                 }
3640         }
3641 }
3642
3643 /**
3644  * Used to be used for outputting text in the installer/updater
3645  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3646  */
3647 function wfOut( $s ) {
3648         wfDeprecated( __FUNCTION__, '1.18' );
3649         global $wgCommandLineMode;
3650         if ( $wgCommandLineMode ) {
3651                 echo $s;
3652         } else {
3653                 echo htmlspecialchars( $s );
3654         }
3655         flush();
3656 }
3657
3658 /**
3659  * Count down from $n to zero on the terminal, with a one-second pause
3660  * between showing each number. For use in command-line scripts.
3661  * @codeCoverageIgnore
3662  * @param $n int
3663  */
3664 function wfCountDown( $n ) {
3665         for ( $i = $n; $i >= 0; $i-- ) {
3666                 if ( $i != $n ) {
3667                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3668                 }
3669                 echo $i;
3670                 flush();
3671                 if ( $i ) {
3672                         sleep( 1 );
3673                 }
3674         }
3675         echo "\n";
3676 }
3677
3678 /**
3679  * Generate a random 32-character hexadecimal token.
3680  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3681  *              characters before hashing.
3682  * @return string
3683  * @codeCoverageIgnore
3684  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3685  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3686  */
3687 function wfGenerateToken( $salt = '' ) {
3688         wfDeprecated( __METHOD__, '1.20' );
3689         $salt = serialize( $salt );
3690         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3691 }
3692
3693 /**
3694  * Replace all invalid characters with -
3695  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3696  * By default, $wgIllegalFileChars = ':'
3697  *
3698  * @param $name Mixed: filename to process
3699  * @return String
3700  */
3701 function wfStripIllegalFilenameChars( $name ) {
3702         global $wgIllegalFileChars;
3703         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3704         $name = wfBaseName( $name );
3705         $name = preg_replace(
3706                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3707                 '-',
3708                 $name
3709         );
3710         return $name;
3711 }
3712
3713 /**
3714  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3715  *
3716  * @return Integer value memory was set to.
3717  */
3718 function wfMemoryLimit() {
3719         global $wgMemoryLimit;
3720         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3721         if ( $memlimit != -1 ) {
3722                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3723                 if ( $conflimit == -1 ) {
3724                         wfDebug( "Removing PHP's memory limit\n" );
3725                         wfSuppressWarnings();
3726                         ini_set( 'memory_limit', $conflimit );
3727                         wfRestoreWarnings();
3728                         return $conflimit;
3729                 } elseif ( $conflimit > $memlimit ) {
3730                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3731                         wfSuppressWarnings();
3732                         ini_set( 'memory_limit', $conflimit );
3733                         wfRestoreWarnings();
3734                         return $conflimit;
3735                 }
3736         }
3737         return $memlimit;
3738 }
3739
3740 /**
3741  * Converts shorthand byte notation to integer form
3742  *
3743  * @param $string String
3744  * @return Integer
3745  */
3746 function wfShorthandToInteger( $string = '' ) {
3747         $string = trim( $string );
3748         if ( $string === '' ) {
3749                 return -1;
3750         }
3751         $last = $string[strlen( $string ) - 1];
3752         $val = intval( $string );
3753         switch( $last ) {
3754                 case 'g':
3755                 case 'G':
3756                         $val *= 1024;
3757                         // break intentionally missing
3758                 case 'm':
3759                 case 'M':
3760                         $val *= 1024;
3761                         // break intentionally missing
3762                 case 'k':
3763                 case 'K':
3764                         $val *= 1024;
3765         }
3766
3767         return $val;
3768 }
3769
3770 /**
3771  * Get the normalised IETF language tag
3772  * See unit test for examples.
3773  *
3774  * @param string $code The language code.
3775  * @return String: The language code which complying with BCP 47 standards.
3776  */
3777 function wfBCP47( $code ) {
3778         $codeSegment = explode( '-', $code );
3779         $codeBCP = array();
3780         foreach ( $codeSegment as $segNo => $seg ) {
3781                 if ( count( $codeSegment ) > 0 ) {
3782                         // when previous segment is x, it is a private segment and should be lc
3783                         if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3784                                 $codeBCP[$segNo] = strtolower( $seg );
3785                         // ISO 3166 country code
3786                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3787                                 $codeBCP[$segNo] = strtoupper( $seg );
3788                         // ISO 15924 script code
3789                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3790                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3791                         // Use lowercase for other cases
3792                         } else {
3793                                 $codeBCP[$segNo] = strtolower( $seg );
3794                         }
3795                 } else {
3796                 // Use lowercase for single segment
3797                         $codeBCP[$segNo] = strtolower( $seg );
3798                 }
3799         }
3800         $langCode = implode( '-', $codeBCP );
3801         return $langCode;
3802 }
3803
3804 /**
3805  * Get a cache object.
3806  *
3807  * @param $inputType integer Cache type, one the the CACHE_* constants.
3808  * @return BagOStuff
3809  */
3810 function wfGetCache( $inputType ) {
3811         return ObjectCache::getInstance( $inputType );
3812 }
3813
3814 /**
3815  * Get the main cache object
3816  *
3817  * @return BagOStuff
3818  */
3819 function wfGetMainCache() {
3820         global $wgMainCacheType;
3821         return ObjectCache::getInstance( $wgMainCacheType );
3822 }
3823
3824 /**
3825  * Get the cache object used by the message cache
3826  *
3827  * @return BagOStuff
3828  */
3829 function wfGetMessageCacheStorage() {
3830         global $wgMessageCacheType;
3831         return ObjectCache::getInstance( $wgMessageCacheType );
3832 }
3833
3834 /**
3835  * Get the cache object used by the parser cache
3836  *
3837  * @return BagOStuff
3838  */
3839 function wfGetParserCacheStorage() {
3840         global $wgParserCacheType;
3841         return ObjectCache::getInstance( $wgParserCacheType );
3842 }
3843
3844 /**
3845  * Get the cache object used by the language converter
3846  *
3847  * @return BagOStuff
3848  */
3849 function wfGetLangConverterCacheStorage() {
3850         global $wgLanguageConverterCacheType;
3851         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3852 }
3853
3854 /**
3855  * Call hook functions defined in $wgHooks
3856  *
3857  * @param string $event event name
3858  * @param array $args parameters passed to hook functions
3859  * @return Boolean True if no handler aborted the hook
3860  */
3861 function wfRunHooks( $event, $args = array() ) {
3862         return Hooks::run( $event, $args );
3863 }
3864
3865 /**
3866  * Wrapper around php's unpack.
3867  *
3868  * @param string $format The format string (See php's docs)
3869  * @param $data: A binary string of binary data
3870  * @param $length integer or false: The minimum length of $data. This is to
3871  *      prevent reading beyond the end of $data. false to disable the check.
3872  *
3873  * Also be careful when using this function to read unsigned 32 bit integer
3874  * because php might make it negative.
3875  *
3876  * @throws MWException if $data not long enough, or if unpack fails
3877  * @return array Associative array of the extracted data
3878  */
3879 function wfUnpack( $format, $data, $length = false ) {
3880         if ( $length !== false ) {
3881                 $realLen = strlen( $data );
3882                 if ( $realLen < $length ) {
3883                         throw new MWException( "Tried to use wfUnpack on a "
3884                                 . "string of length $realLen, but needed one "
3885                                 . "of at least length $length."
3886                         );
3887                 }
3888         }
3889
3890         wfSuppressWarnings();
3891         $result = unpack( $format, $data );
3892         wfRestoreWarnings();
3893
3894         if ( $result === false ) {
3895                 // If it cannot extract the packed data.
3896                 throw new MWException( "unpack could not unpack binary data" );
3897         }
3898         return $result;
3899 }
3900
3901 /**
3902  * Determine if an image exists on the 'bad image list'.
3903  *
3904  * The format of MediaWiki:Bad_image_list is as follows:
3905  *    * Only list items (lines starting with "*") are considered
3906  *    * The first link on a line must be a link to a bad image
3907  *    * Any subsequent links on the same line are considered to be exceptions,
3908  *      i.e. articles where the image may occur inline.
3909  *
3910  * @param string $name the image name to check
3911  * @param $contextTitle Title|bool the page on which the image occurs, if known
3912  * @param string $blacklist wikitext of a file blacklist
3913  * @return bool
3914  */
3915 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3916         static $badImageCache = null; // based on bad_image_list msg
3917         wfProfileIn( __METHOD__ );
3918
3919         # Handle redirects
3920         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3921         if ( $redirectTitle ) {
3922                 $name = $redirectTitle->getDBkey();
3923         }
3924
3925         # Run the extension hook
3926         $bad = false;
3927         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3928                 wfProfileOut( __METHOD__ );
3929                 return $bad;
3930         }
3931
3932         $cacheable = ( $blacklist === null );
3933         if ( $cacheable && $badImageCache !== null ) {
3934                 $badImages = $badImageCache;
3935         } else { // cache miss
3936                 if ( $blacklist === null ) {
3937                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3938                 }
3939                 # Build the list now
3940                 $badImages = array();
3941                 $lines = explode( "\n", $blacklist );
3942                 foreach ( $lines as $line ) {
3943                         # List items only
3944                         if ( substr( $line, 0, 1 ) !== '*' ) {
3945                                 continue;
3946                         }
3947
3948                         # Find all links
3949                         $m = array();
3950                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3951                                 continue;
3952                         }
3953
3954                         $exceptions = array();
3955                         $imageDBkey = false;
3956                         foreach ( $m[1] as $i => $titleText ) {
3957                                 $title = Title::newFromText( $titleText );
3958                                 if ( !is_null( $title ) ) {
3959                                         if ( $i == 0 ) {
3960                                                 $imageDBkey = $title->getDBkey();
3961                                         } else {
3962                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3963                                         }
3964                                 }
3965                         }
3966
3967                         if ( $imageDBkey !== false ) {
3968                                 $badImages[$imageDBkey] = $exceptions;
3969                         }
3970                 }
3971                 if ( $cacheable ) {
3972                         $badImageCache = $badImages;
3973                 }
3974         }
3975
3976         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3977         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3978         wfProfileOut( __METHOD__ );
3979         return $bad;
3980 }