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 /// @endcond
  97
  98 /**
  99  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 100  * @param $a array
 101  * @param $b array
 102  * @return array
 103  */
 104 function wfArrayDiff2( $a, $b ) {
 105         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 106 }
 107
 108 /**
 109  * @param $a
 110  * @param $b
 111  * @return int
 112  */
 113 function wfArrayDiff2_cmp( $a, $b ) {
 114         if ( !is_array( $a ) ) {
 115                 return strcmp( $a, $b );
 116         } elseif ( count( $a ) !== count( $b ) ) {
 117                 return count( $a ) < count( $b ) ? -1 : 1;
 118         } else {
 119                 reset( $a );
 120                 reset( $b );
 121                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 122                         $cmp = strcmp( $valueA, $valueB );
 123                         if ( $cmp !== 0 ) {
 124                                 return $cmp;
 125                         }
 126                 }
 127                 return 0;
 128         }
 129 }
 130
 131 /**
 132  * Array lookup
 133  * Returns an array where the values in array $b are replaced by the
 134  * values in array $a with the corresponding keys
 135  *
 136  * @deprecated since 1.22; use array_intersect_key()
 137  * @param $a Array
 138  * @param $b Array
 139  * @return array
 140  */
 141 function wfArrayLookup( $a, $b ) {
 142         wfDeprecated( __FUNCTION__, '1.22' );
 143         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 144 }
 145
 146 /**
 147  * Appends to second array if $value differs from that in $default
 148  *
 149  * @param $key String|Int
 150  * @param $value Mixed
 151  * @param $default Mixed
 152  * @param array $changed to alter
 153  * @throws MWException
 154  */
 155 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 156         if ( is_null( $changed ) ) {
 157                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 158         }
 159         if ( $default[$key] !== $value ) {
 160                 $changed[$key] = $value;
 161         }
 162 }
 163
 164 /**
 165  * Backwards array plus for people who haven't bothered to read the PHP manual
 166  * XXX: will not darn your socks for you.
 167  *
 168  * @deprecated since 1.22; use array_replace()
 169  * @param $array1 Array
 170  * @param [$array2, [...]] Arrays
 171  * @return Array
 172  */
 173 function wfArrayMerge( $array1/* ... */ ) {
 174         wfDeprecated( __FUNCTION__, '1.22' );
 175         $args = func_get_args();
 176         $args = array_reverse( $args, true );
 177         $out = array();
 178         foreach ( $args as $arg ) {
 179                 $out += $arg;
 180         }
 181         return $out;
 182 }
 183
 184 /**
 185  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 186  * e.g.
 187  *      wfMergeErrorArrays(
 188  *              array( array( 'x' ) ),
 189  *              array( array( 'x', '2' ) ),
 190  *              array( array( 'x' ) ),
 191  *              array( array( 'y' ) )
 192  *      );
 193  * returns:
 194  *              array(
 195  *              array( 'x', '2' ),
 196  *              array( 'x' ),
 197  *              array( 'y' )
 198  *      )
 199  * @param varargs
 200  * @return Array
 201  */
 202 function wfMergeErrorArrays( /*...*/ ) {
 203         $args = func_get_args();
 204         $out = array();
 205         foreach ( $args as $errors ) {
 206                 foreach ( $errors as $params ) {
 207                         # @todo FIXME: Sometimes get nested arrays for $params,
 208                         # which leads to E_NOTICEs
 209                         $spec = implode( "\t", $params );
 210                         $out[$spec] = $params;
 211                 }
 212         }
 213         return array_values( $out );
 214 }
 215
 216 /**
 217  * Insert array into another array after the specified *KEY*
 218  *
 219  * @param array $array The array.
 220  * @param array $insert The array to insert.
 221  * @param $after Mixed: The key to insert after
 222  * @return Array
 223  */
 224 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 225         // Find the offset of the element to insert after.
 226         $keys = array_keys( $array );
 227         $offsetByKey = array_flip( $keys );
 228
 229         $offset = $offsetByKey[$after];
 230
 231         // Insert at the specified offset
 232         $before = array_slice( $array, 0, $offset + 1, true );
 233         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 234
 235         $output = $before + $insert + $after;
 236
 237         return $output;
 238 }
 239
 240 /**
 241  * Recursively converts the parameter (an object) to an array with the same data
 242  *
 243  * @param $objOrArray Object|Array
 244  * @param $recursive Bool
 245  * @return Array
 246  */
 247 function wfObjectToArray( $objOrArray, $recursive = true ) {
 248         $array = array();
 249         if ( is_object( $objOrArray ) ) {
 250                 $objOrArray = get_object_vars( $objOrArray );
 251         }
 252         foreach ( $objOrArray as $key => $value ) {
 253                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 254                         $value = wfObjectToArray( $value );
 255                 }
 256
 257                 $array[$key] = $value;
 258         }
 259
 260         return $array;
 261 }
 262
 263 /**
 264  * Get a random decimal value between 0 and 1, in a way
 265  * not likely to give duplicate values for any realistic
 266  * number of articles.
 267  *
 268  * @return string
 269  */
 270 function wfRandom() {
 271         # The maximum random value is "only" 2^31-1, so get two random
 272         # values to reduce the chance of dupes
 273         $max = mt_getrandmax() + 1;
 274         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 275                 / $max / $max, 12, '.', '' );
 276         return $rand;
 277 }
 278
 279 /**
 280  * Get a random string containing a number of pseudo-random hex
 281  * characters.
 282  * @note This is not secure, if you are trying to generate some sort
 283  *       of token please use MWCryptRand instead.
 284  *
 285  * @param int $length The length of the string to generate
 286  * @return String
 287  * @since 1.20
 288  */
 289 function wfRandomString( $length = 32 ) {
 290         $str = '';
 291         for ( $n = 0; $n < $length; $n += 7 ) {
 292                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 293         }
 294         return substr( $str, 0, $length );
 295 }
 296
 297 /**
 298  * We want some things to be included as literal characters in our title URLs
 299  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 300  * all of the following should be safe:
 301  *
 302  * ;:@&=$-_.+!*'(),
 303  *
 304  * But + is not safe because it's used to indicate a space; &= are only safe in
 305  * paths and not in queries (and we don't distinguish here); ' seems kind of
 306  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 307  * is reserved, we don't care.  So the list we unescape is:
 308  *
 309  * ;:@$!*(),/
 310  *
 311  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 312  * so no fancy : for IIS7.
 313  *
 314  * %2F in the page titles seems to fatally break for some reason.
 315  *
 316  * @param $s String:
 317  * @return string
 318  */
 319 function wfUrlencode( $s ) {
 320         static $needle;
 321         if ( is_null( $s ) ) {
 322                 $needle = null;
 323                 return '';
 324         }
 325
 326         if ( is_null( $needle ) ) {
 327                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 328                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 329                         $needle[] = '%3A';
 330                 }
 331         }
 332
 333         $s = urlencode( $s );
 334         $s = str_ireplace(
 335                 $needle,
 336                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 337                 $s
 338         );
 339
 340         return $s;
 341 }
 342
 343 /**
 344  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 345  * "days=7&limit=100". Options in the first array override options in the second.
 346  * Options set to null or false will not be output.
 347  *
 348  * @param array $array1 ( String|Array )
 349  * @param array $array2 ( String|Array )
 350  * @param $prefix String
 351  * @return String
 352  */
 353 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 354         if ( !is_null( $array2 ) ) {
 355                 $array1 = $array1 + $array2;
 356         }
 357
 358         $cgi = '';
 359         foreach ( $array1 as $key => $value ) {
 360                 if ( !is_null( $value ) && $value !== false ) {
 361                         if ( $cgi != '' ) {
 362                                 $cgi .= '&';
 363                         }
 364                         if ( $prefix !== '' ) {
 365                                 $key = $prefix . "[$key]";
 366                         }
 367                         if ( is_array( $value ) ) {
 368                                 $firstTime = true;
 369                                 foreach ( $value as $k => $v ) {
 370                                         $cgi .= $firstTime ? '' : '&';
 371                                         if ( is_array( $v ) ) {
 372                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 373                                         } else {
 374                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 375                                         }
 376                                         $firstTime = false;
 377                                 }
 378                         } else {
 379                                 if ( is_object( $value ) ) {
 380                                         $value = $value->__toString();
 381                                 }
 382                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 383                         }
 384                 }
 385         }
 386         return $cgi;
 387 }
 388
 389 /**
 390  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 391  * its argument and returns the same string in array form.  This allows compatibility
 392  * with legacy functions that accept raw query strings instead of nice
 393  * arrays.  Of course, keys and values are urldecode()d.
 394  *
 395  * @param string $query query string
 396  * @return array Array version of input
 397  */
 398 function wfCgiToArray( $query ) {
 399         if ( isset( $query[0] ) && $query[0] == '?' ) {
 400                 $query = substr( $query, 1 );
 401         }
 402         $bits = explode( '&', $query );
 403         $ret = array();
 404         foreach ( $bits as $bit ) {
 405                 if ( $bit === '' ) {
 406                         continue;
 407                 }
 408                 if ( strpos( $bit, '=' ) === false ) {
 409                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 410                         $key = $bit;
 411                         $value = '';
 412                 } else {
 413                         list( $key, $value ) = explode( '=', $bit );
 414                 }
 415                 $key = urldecode( $key );
 416                 $value = urldecode( $value );
 417                 if ( strpos( $key, '[' ) !== false ) {
 418                         $keys = array_reverse( explode( '[', $key ) );
 419                         $key = array_pop( $keys );
 420                         $temp = $value;
 421                         foreach ( $keys as $k ) {
 422                                 $k = substr( $k, 0, -1 );
 423                                 $temp = array( $k => $temp );
 424                         }
 425                         if ( isset( $ret[$key] ) ) {
 426                                 $ret[$key] = array_merge( $ret[$key], $temp );
 427                         } else {
 428                                 $ret[$key] = $temp;
 429                         }
 430                 } else {
 431                         $ret[$key] = $value;
 432                 }
 433         }
 434         return $ret;
 435 }
 436
 437 /**
 438  * Append a query string to an existing URL, which may or may not already
 439  * have query string parameters already. If so, they will be combined.
 440  *
 441  * @param $url String
 442  * @param $query Mixed: string or associative array
 443  * @return string
 444  */
 445 function wfAppendQuery( $url, $query ) {
 446         if ( is_array( $query ) ) {
 447                 $query = wfArrayToCgi( $query );
 448         }
 449         if ( $query != '' ) {
 450                 if ( false === strpos( $url, '?' ) ) {
 451                         $url .= '?';
 452                 } else {
 453                         $url .= '&';
 454                 }
 455                 $url .= $query;
 456         }
 457         return $url;
 458 }
 459
 460 /**
 461  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 462  * is correct.
 463  *
 464  * The meaning of the PROTO_* constants is as follows:
 465  * PROTO_HTTP: Output a URL starting with http://
 466  * PROTO_HTTPS: Output a URL starting with https://
 467  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 468  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 469  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 470  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 471  *
 472  * @todo this won't work with current-path-relative URLs
 473  * like "subdir/foo.html", etc.
 474  *
 475  * @param string $url either fully-qualified or a local path + query
 476  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 477  *                             protocol to use if $url or $wgServer is
 478  *                             protocol-relative
 479  * @return string Fully-qualified URL, current-path-relative URL or false if
 480  *                no valid URL can be constructed
 481  */
 482 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 483         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 484         $serverUrl = $wgServer;
 485         if ( $defaultProto === PROTO_CANONICAL ) {
 486                 $serverUrl = $wgCanonicalServer;
 487         }
 488         // Make $wgInternalServer fall back to $wgServer if not set
 489         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 490                 $serverUrl = $wgInternalServer;
 491         }
 492         if ( $defaultProto === PROTO_CURRENT ) {
 493                 $defaultProto = WebRequest::detectProtocol() . '://';
 494         }
 495
 496         // Analyze $serverUrl to obtain its protocol
 497         $bits = wfParseUrl( $serverUrl );
 498         $serverHasProto = $bits && $bits['scheme'] != '';
 499
 500         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 501                 if ( $serverHasProto ) {
 502                         $defaultProto = $bits['scheme'] . '://';
 503                 } else {
 504                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 505                         // Fall back to HTTP in this ridiculous case
 506                         $defaultProto = PROTO_HTTP;
 507                 }
 508         }
 509
 510         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 511
 512         if ( substr( $url, 0, 2 ) == '//' ) {
 513                 $url = $defaultProtoWithoutSlashes . $url;
 514         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 515                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 516                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 517         }
 518
 519         $bits = wfParseUrl( $url );
 520         if ( $bits && isset( $bits['path'] ) ) {
 521                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 522                 return wfAssembleUrl( $bits );
 523         } elseif ( $bits ) {
 524                 # No path to expand
 525                 return $url;
 526         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 527                 # URL is a relative path
 528                 return wfRemoveDotSegments( $url );
 529         }
 530
 531         # Expanded URL is not valid.
 532         return false;
 533 }
 534
 535 /**
 536  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 537  * if you need to edit part of a URL and put it back together.
 538  *
 539  * This is the basic structure used (brackets contain keys for $urlParts):
 540  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 541  *
 542  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 543  *
 544  * @since 1.19
 545  * @param array $urlParts URL parts, as output from wfParseUrl
 546  * @return string URL assembled from its component parts
 547  */
 548 function wfAssembleUrl( $urlParts ) {
 549         $result = '';
 550
 551         if ( isset( $urlParts['delimiter'] ) ) {
 552                 if ( isset( $urlParts['scheme'] ) ) {
 553                         $result .= $urlParts['scheme'];
 554                 }
 555
 556                 $result .= $urlParts['delimiter'];
 557         }
 558
 559         if ( isset( $urlParts['host'] ) ) {
 560                 if ( isset( $urlParts['user'] ) ) {
 561                         $result .= $urlParts['user'];
 562                         if ( isset( $urlParts['pass'] ) ) {
 563                                 $result .= ':' . $urlParts['pass'];
 564                         }
 565                         $result .= '@';
 566                 }
 567
 568                 $result .= $urlParts['host'];
 569
 570                 if ( isset( $urlParts['port'] ) ) {
 571                         $result .= ':' . $urlParts['port'];
 572                 }
 573         }
 574
 575         if ( isset( $urlParts['path'] ) ) {
 576                 $result .= $urlParts['path'];
 577         }
 578
 579         if ( isset( $urlParts['query'] ) ) {
 580                 $result .= '?' . $urlParts['query'];
 581         }
 582
 583         if ( isset( $urlParts['fragment'] ) ) {
 584                 $result .= '#' . $urlParts['fragment'];
 585         }
 586
 587         return $result;
 588 }
 589
 590 /**
 591  * Remove all dot-segments in the provided URL path.  For example,
 592  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 593  * RFC3986 section 5.2.4.
 594  *
 595  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 596  *
 597  * @param string $urlPath URL path, potentially containing dot-segments
 598  * @return string URL path with all dot-segments removed
 599  */
 600 function wfRemoveDotSegments( $urlPath ) {
 601         $output = '';
 602         $inputOffset = 0;
 603         $inputLength = strlen( $urlPath );
 604
 605         while ( $inputOffset < $inputLength ) {
 606                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 607                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 608                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 609                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 610                 $trimOutput = false;
 611
 612                 if ( $prefixLengthTwo == './' ) {
 613                         # Step A, remove leading "./"
 614                         $inputOffset += 2;
 615                 } elseif ( $prefixLengthThree == '../' ) {
 616                         # Step A, remove leading "../"
 617                         $inputOffset += 3;
 618                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 619                         # Step B, replace leading "/.$" with "/"
 620                         $inputOffset += 1;
 621                         $urlPath[$inputOffset] = '/';
 622                 } elseif ( $prefixLengthThree == '/./' ) {
 623                         # Step B, replace leading "/./" with "/"
 624                         $inputOffset += 2;
 625                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 626                         # Step C, replace leading "/..$" with "/" and
 627                         # remove last path component in output
 628                         $inputOffset += 2;
 629                         $urlPath[$inputOffset] = '/';
 630                         $trimOutput = true;
 631                 } elseif ( $prefixLengthFour == '/../' ) {
 632                         # Step C, replace leading "/../" with "/" and
 633                         # remove last path component in output
 634                         $inputOffset += 3;
 635                         $trimOutput = true;
 636                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 637                         # Step D, remove "^.$"
 638                         $inputOffset += 1;
 639                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 640                         # Step D, remove "^..$"
 641                         $inputOffset += 2;
 642                 } else {
 643                         # Step E, move leading path segment to output
 644                         if ( $prefixLengthOne == '/' ) {
 645                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 646                         } else {
 647                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 648                         }
 649                         if ( $slashPos === false ) {
 650                                 $output .= substr( $urlPath, $inputOffset );
 651                                 $inputOffset = $inputLength;
 652                         } else {
 653                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 654                                 $inputOffset += $slashPos - $inputOffset;
 655                         }
 656                 }
 657
 658                 if ( $trimOutput ) {
 659                         $slashPos = strrpos( $output, '/' );
 660                         if ( $slashPos === false ) {
 661                                 $output = '';
 662                         } else {
 663                                 $output = substr( $output, 0, $slashPos );
 664                         }
 665                 }
 666         }
 667
 668         return $output;
 669 }
 670
 671 /**
 672  * Returns a regular expression of url protocols
 673  *
 674  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 675  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 676  * @return String
 677  */
 678 function wfUrlProtocols( $includeProtocolRelative = true ) {
 679         global $wgUrlProtocols;
 680
 681         // Cache return values separately based on $includeProtocolRelative
 682         static $withProtRel = null, $withoutProtRel = null;
 683         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 684         if ( !is_null( $cachedValue ) ) {
 685                 return $cachedValue;
 686         }
 687
 688         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 689         // with LocalSettings files from 1.5
 690         if ( is_array( $wgUrlProtocols ) ) {
 691                 $protocols = array();
 692                 foreach ( $wgUrlProtocols as $protocol ) {
 693                         // Filter out '//' if !$includeProtocolRelative
 694                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 695                                 $protocols[] = preg_quote( $protocol, '/' );
 696                         }
 697                 }
 698
 699                 $retval = implode( '|', $protocols );
 700         } else {
 701                 // Ignore $includeProtocolRelative in this case
 702                 // This case exists for pre-1.6 compatibility, and we can safely assume
 703                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 704                 // URLs weren't supported until 1.18
 705                 $retval = $wgUrlProtocols;
 706         }
 707
 708         // Cache return value
 709         if ( $includeProtocolRelative ) {
 710                 $withProtRel = $retval;
 711         } else {
 712                 $withoutProtRel = $retval;
 713         }
 714         return $retval;
 715 }
 716
 717 /**
 718  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 719  * you need a regex that matches all URL protocols but does not match protocol-
 720  * relative URLs
 721  * @return String
 722  */
 723 function wfUrlProtocolsWithoutProtRel() {
 724         return wfUrlProtocols( false );
 725 }
 726
 727 /**
 728  * parse_url() work-alike, but non-broken.  Differences:
 729  *
 730  * 1) Does not raise warnings on bad URLs (just returns false)
 731  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 732  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 733  *
 734  * @param string $url a URL to parse
 735  * @return Array: bits of the URL in an associative array, per PHP docs
 736  */
 737 function wfParseUrl( $url ) {
 738         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 739
 740         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 741         // way to handle them is to just prepend 'http:' and strip the protocol out later
 742         $wasRelative = substr( $url, 0, 2 ) == '//';
 743         if ( $wasRelative ) {
 744                 $url = "http:$url";
 745         }
 746         wfSuppressWarnings();
 747         $bits = parse_url( $url );
 748         wfRestoreWarnings();
 749         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 750         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 751         if ( !$bits || !isset( $bits['scheme'] ) ) {
 752                 return false;
 753         }
 754
 755         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 756         $bits['scheme'] = strtolower( $bits['scheme'] );
 757
 758         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 759         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 760                 $bits['delimiter'] = '://';
 761         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 762                 $bits['delimiter'] = ':';
 763                 // parse_url detects for news: and mailto: the host part of an url as path
 764                 // We have to correct this wrong detection
 765                 if ( isset( $bits['path'] ) ) {
 766                         $bits['host'] = $bits['path'];
 767                         $bits['path'] = '';
 768                 }
 769         } else {
 770                 return false;
 771         }
 772
 773         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 774         if ( !isset( $bits['host'] ) ) {
 775                 $bits['host'] = '';
 776
 777                 // bug 45069
 778                 if ( isset( $bits['path'] ) ) {
 779                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 780                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 781                                 $bits['path'] = '/' . $bits['path'];
 782                         }
 783                 } else {
 784                         $bits['path'] = '';
 785                 }
 786         }
 787
 788         // If the URL was protocol-relative, fix scheme and delimiter
 789         if ( $wasRelative ) {
 790                 $bits['scheme'] = '';
 791                 $bits['delimiter'] = '//';
 792         }
 793         return $bits;
 794 }
 795
 796 /**
 797  * Take a URL, make sure it's expanded to fully qualified, and replace any
 798  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 799  * for more compact display and legibility for local audiences.
 800  *
 801  * @todo handle punycode domains too
 802  *
 803  * @param $url string
 804  * @return string
 805  */
 806 function wfExpandIRI( $url ) {
 807         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 808 }
 809
 810 /**
 811  * Private callback for wfExpandIRI
 812  * @param array $matches
 813  * @return string
 814  */
 815 function wfExpandIRI_callback( $matches ) {
 816         return urldecode( $matches[1] );
 817 }
 818
 819 /**
 820  * Make URL indexes, appropriate for the el_index field of externallinks.
 821  *
 822  * @param $url String
 823  * @return array
 824  */
 825 function wfMakeUrlIndexes( $url ) {
 826         $bits = wfParseUrl( $url );
 827
 828         // Reverse the labels in the hostname, convert to lower case
 829         // For emails reverse domainpart only
 830         if ( $bits['scheme'] == 'mailto' ) {
 831                 $mailparts = explode( '@', $bits['host'], 2 );
 832                 if ( count( $mailparts ) === 2 ) {
 833                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 834                 } else {
 835                         // No domain specified, don't mangle it
 836                         $domainpart = '';
 837                 }
 838                 $reversedHost = $domainpart . '@' . $mailparts[0];
 839         } else {
 840                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 841         }
 842         // Add an extra dot to the end
 843         // Why? Is it in wrong place in mailto links?
 844         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 845                 $reversedHost .= '.';
 846         }
 847         // Reconstruct the pseudo-URL
 848         $prot = $bits['scheme'];
 849         $index = $prot . $bits['delimiter'] . $reversedHost;
 850         // Leave out user and password. Add the port, path, query and fragment
 851         if ( isset( $bits['port'] ) ) {
 852                 $index .= ':' . $bits['port'];
 853         }
 854         if ( isset( $bits['path'] ) ) {
 855                 $index .= $bits['path'];
 856         } else {
 857                 $index .= '/';
 858         }
 859         if ( isset( $bits['query'] ) ) {
 860                 $index .= '?' . $bits['query'];
 861         }
 862         if ( isset( $bits['fragment'] ) ) {
 863                 $index .= '#' . $bits['fragment'];
 864         }
 865
 866         if ( $prot == '' ) {
 867                 return array( "http:$index", "https:$index" );
 868         } else {
 869                 return array( $index );
 870         }
 871 }
 872
 873 /**
 874  * Check whether a given URL has a domain that occurs in a given set of domains
 875  * @param string $url URL
 876  * @param array $domains Array of domains (strings)
 877  * @return bool True if the host part of $url ends in one of the strings in $domains
 878  */
 879 function wfMatchesDomainList( $url, $domains ) {
 880         $bits = wfParseUrl( $url );
 881         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 882                 foreach ( (array)$domains as $domain ) {
 883                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 884                         // We should use something that interprets dots instead
 885                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 886                                 return true;
 887                         }
 888                 }
 889         }
 890         return false;
 891 }
 892
 893 /**
 894  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 895  * In normal operation this is a NOP.
 896  *
 897  * Controlling globals:
 898  * $wgDebugLogFile - points to the log file
 899  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 900  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 901  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 902  *
 903  * @param $text String
 904  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 905  */
 906 function wfDebug( $text, $logonly = false ) {
 907         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 908
 909         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 910                 return;
 911         }
 912
 913         $timer = wfDebugTimer();
 914         if ( $timer !== '' ) {
 915                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 916         }
 917
 918         if ( !$logonly ) {
 919                 MWDebug::debugMsg( $text );
 920         }
 921
 922         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 923                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 924                         # Strip unprintables; they can switch terminal modes when binary data
 925                         # gets dumped, which is pretty annoying.
 926                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 927                         $text = $wgDebugLogPrefix . $text;
 928                         wfErrorLog( $text, $wgDebugLogFile );
 929                 }
 930         }
 931 }
 932
 933 /**
 934  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 935  * @return bool
 936  */
 937 function wfIsDebugRawPage() {
 938         static $cache;
 939         if ( $cache !== null ) {
 940                 return $cache;
 941         }
 942         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 943         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 944                 || (
 945                         isset( $_SERVER['SCRIPT_NAME'] )
 946                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 947                 ) )
 948         {
 949                 $cache = true;
 950         } else {
 951                 $cache = false;
 952         }
 953         return $cache;
 954 }
 955
 956 /**
 957  * Get microsecond timestamps for debug logs
 958  *
 959  * @return string
 960  */
 961 function wfDebugTimer() {
 962         global $wgDebugTimestamps, $wgRequestTime;
 963
 964         if ( !$wgDebugTimestamps ) {
 965                 return '';
 966         }
 967
 968         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 969         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 970         return "$prefix $mem  ";
 971 }
 972
 973 /**
 974  * Send a line giving PHP memory usage.
 975  *
 976  * @param bool $exact print exact values instead of kilobytes (default: false)
 977  */
 978 function wfDebugMem( $exact = false ) {
 979         $mem = memory_get_usage();
 980         if ( !$exact ) {
 981                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 982         } else {
 983                 $mem .= ' bytes';
 984         }
 985         wfDebug( "Memory usage: $mem\n" );
 986 }
 987
 988 /**
 989  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 990  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 991  *
 992  * @param $logGroup String
 993  * @param $text String
 994  * @param bool $public whether to log the event in the public log if no private
 995  *                     log file is specified, (default true)
 996  */
 997 function wfDebugLog( $logGroup, $text, $public = true ) {
 998         global $wgDebugLogGroups;
 999         $text = trim( $text ) . "\n";
1000         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1001                 $time = wfTimestamp( TS_DB );
1002                 $wiki = wfWikiID();
1003                 $host = wfHostname();
1004                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1005                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1006                 }
1007         } elseif ( $public === true ) {
1008                 wfDebug( "[$logGroup] $text", false );
1009         }
1010 }
1011
1012 /**
1013  * Log for database errors
1014  *
1015  * @param string $text database error message.
1016  */
1017 function wfLogDBError( $text ) {
1018         global $wgDBerrorLog, $wgDBerrorLogTZ;
1019         static $logDBErrorTimeZoneObject = null;
1020
1021         if ( $wgDBerrorLog ) {
1022                 $host = wfHostname();
1023                 $wiki = wfWikiID();
1024
1025                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1026                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1027                 }
1028
1029                 // Workaround for https://bugs.php.net/bug.php?id=52063
1030                 // Can be removed when min PHP > 5.3.2
1031                 if ( $logDBErrorTimeZoneObject === null ) {
1032                         $d = date_create( "now" );
1033                 } else {
1034                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1035                 }
1036
1037                 $date = $d->format( 'D M j G:i:s T Y' );
1038
1039                 $text = "$date\t$host\t$wiki\t$text";
1040                 wfErrorLog( $text, $wgDBerrorLog );
1041         }
1042 }
1043
1044 /**
1045  * Throws a warning that $function is deprecated
1046  *
1047  * @param $function String
1048  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1049  * @param string|bool $component Added in 1.19.
1050  * @param $callerOffset integer: How far up the call stack is the original
1051  *    caller. 2 = function that called the function that called
1052  *    wfDeprecated (Added in 1.20)
1053  *
1054  * @return null
1055  */
1056 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1057         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1058 }
1059
1060 /**
1061  * Send a warning either to the debug log or in a PHP error depending on
1062  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1063  *
1064  * @param string $msg message to send
1065  * @param $callerOffset Integer: number of items to go back in the backtrace to
1066  *        find the correct caller (1 = function calling wfWarn, ...)
1067  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1068  *        only used when $wgDevelopmentWarnings is true
1069  */
1070 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1071         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1072 }
1073
1074 /**
1075  * Send a warning as a PHP error and the debug log. This is intended for logging
1076  * warnings in production. For logging development warnings, use WfWarn instead.
1077  *
1078  * @param $msg String: message to send
1079  * @param $callerOffset Integer: number of items to go back in the backtrace to
1080  *        find the correct caller (1 = function calling wfLogWarning, ...)
1081  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1082  */
1083 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1084         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1085 }
1086
1087 /**
1088  * Log to a file without getting "file size exceeded" signals.
1089  *
1090  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1091  * send lines to the specified port, prefixed by the specified prefix and a space.
1092  *
1093  * @param $text String
1094  * @param string $file filename
1095  * @throws MWException
1096  */
1097 function wfErrorLog( $text, $file ) {
1098         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1099                 # Needs the sockets extension
1100                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1101                         // IPv6 bracketed host
1102                         $host = $m[2];
1103                         $port = intval( $m[3] );
1104                         $prefix = isset( $m[4] ) ? $m[4] : false;
1105                         $domain = AF_INET6;
1106                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1107                         $host = $m[2];
1108                         if ( !IP::isIPv4( $host ) ) {
1109                                 $host = gethostbyname( $host );
1110                         }
1111                         $port = intval( $m[3] );
1112                         $prefix = isset( $m[4] ) ? $m[4] : false;
1113                         $domain = AF_INET;
1114                 } else {
1115                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1116                 }
1117
1118                 // Clean it up for the multiplexer
1119                 if ( strval( $prefix ) !== '' ) {
1120                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1121
1122                         // Limit to 64KB
1123                         if ( strlen( $text ) > 65506 ) {
1124                                 $text = substr( $text, 0, 65506 );
1125                         }
1126
1127                         if ( substr( $text, -1 ) != "\n" ) {
1128                                 $text .= "\n";
1129                         }
1130                 } elseif ( strlen( $text ) > 65507 ) {
1131                         $text = substr( $text, 0, 65507 );
1132                 }
1133
1134                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1135                 if ( !$sock ) {
1136                         return;
1137                 }
1138
1139                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1140                 socket_close( $sock );
1141         } else {
1142                 wfSuppressWarnings();
1143                 $exists = file_exists( $file );
1144                 $size = $exists ? filesize( $file ) : false;
1145                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1146                         file_put_contents( $file, $text, FILE_APPEND );
1147                 }
1148                 wfRestoreWarnings();
1149         }
1150 }
1151
1152 /**
1153  * @todo document
1154  */
1155 function wfLogProfilingData() {
1156         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1157         global $wgProfileLimit, $wgUser;
1158
1159         StatCounter::singleton()->flush();
1160
1161         $profiler = Profiler::instance();
1162
1163         # Profiling must actually be enabled...
1164         if ( $profiler->isStub() ) {
1165                 return;
1166         }
1167
1168         // Get total page request time and only show pages that longer than
1169         // $wgProfileLimit time (default is 0)
1170         $elapsed = microtime( true ) - $wgRequestTime;
1171         if ( $elapsed <= $wgProfileLimit ) {
1172                 return;
1173         }
1174
1175         $profiler->logData();
1176
1177         // Check whether this should be logged in the debug file.
1178         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1179                 return;
1180         }
1181
1182         $forward = '';
1183         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1184                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1185         }
1186         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1187                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1188         }
1189         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1190                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1191         }
1192         if ( $forward ) {
1193                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1194         }
1195         // Don't load $wgUser at this late stage just for statistics purposes
1196         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1197         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1198                 $forward .= ' anon';
1199         }
1200
1201         // Command line script uses a FauxRequest object which does not have
1202         // any knowledge about an URL and throw an exception instead.
1203         try {
1204                 $requestUrl = $wgRequest->getRequestURL();
1205         } catch ( MWException $e ) {
1206                 $requestUrl = 'n/a';
1207         }
1208
1209         $log = sprintf( "%s\t%04.3f\t%s\n",
1210                 gmdate( 'YmdHis' ), $elapsed,
1211                 urldecode( $requestUrl . $forward ) );
1212
1213         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1214 }
1215
1216 /**
1217  * Increment a statistics counter
1218  *
1219  * @param $key String
1220  * @param $count Int
1221  * @return void
1222  */
1223 function wfIncrStats( $key, $count = 1 ) {
1224         StatCounter::singleton()->incr( $key, $count );
1225 }
1226
1227 /**
1228  * Check if the wiki read-only lock file is present. This can be used to lock
1229  * off editing functions, but doesn't guarantee that the database will not be
1230  * modified.
1231  *
1232  * @return bool
1233  */
1234 function wfReadOnly() {
1235         global $wgReadOnlyFile, $wgReadOnly;
1236
1237         if ( !is_null( $wgReadOnly ) ) {
1238                 return (bool)$wgReadOnly;
1239         }
1240         if ( $wgReadOnlyFile == '' ) {
1241                 return false;
1242         }
1243         // Set $wgReadOnly for faster access next time
1244         if ( is_file( $wgReadOnlyFile ) ) {
1245                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1246         } else {
1247                 $wgReadOnly = false;
1248         }
1249         return (bool)$wgReadOnly;
1250 }
1251
1252 /**
1253  * @return bool
1254  */
1255 function wfReadOnlyReason() {
1256         global $wgReadOnly;
1257         wfReadOnly();
1258         return $wgReadOnly;
1259 }
1260
1261 /**
1262  * Return a Language object from $langcode
1263  *
1264  * @param $langcode Mixed: either:
1265  *                  - a Language object
1266  *                  - code of the language to get the message for, if it is
1267  *                    a valid code create a language for that language, if
1268  *                    it is a string but not a valid code then make a basic
1269  *                    language object
1270  *                  - a boolean: if it's false then use the global object for
1271  *                    the current user's language (as a fallback for the old parameter
1272  *                    functionality), or if it is true then use global object
1273  *                    for the wiki's content language.
1274  * @return Language object
1275  */
1276 function wfGetLangObj( $langcode = false ) {
1277         # Identify which language to get or create a language object for.
1278         # Using is_object here due to Stub objects.
1279         if ( is_object( $langcode ) ) {
1280                 # Great, we already have the object (hopefully)!
1281                 return $langcode;
1282         }
1283
1284         global $wgContLang, $wgLanguageCode;
1285         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1286                 # $langcode is the language code of the wikis content language object.
1287                 # or it is a boolean and value is true
1288                 return $wgContLang;
1289         }
1290
1291         global $wgLang;
1292         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1293                 # $langcode is the language code of user language object.
1294                 # or it was a boolean and value is false
1295                 return $wgLang;
1296         }
1297
1298         $validCodes = array_keys( Language::fetchLanguageNames() );
1299         if ( in_array( $langcode, $validCodes ) ) {
1300                 # $langcode corresponds to a valid language.
1301                 return Language::factory( $langcode );
1302         }
1303
1304         # $langcode is a string, but not a valid language code; use content language.
1305         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1306         return $wgContLang;
1307 }
1308
1309 /**
1310  * Old function when $wgBetterDirectionality existed
1311  * All usage removed, wfUILang can be removed in near future
1312  *
1313  * @deprecated since 1.18
1314  * @return Language
1315  */
1316 function wfUILang() {
1317         wfDeprecated( __METHOD__, '1.18' );
1318         global $wgLang;
1319         return $wgLang;
1320 }
1321
1322 /**
1323  * This is the function for getting translated interface messages.
1324  *
1325  * @see Message class for documentation how to use them.
1326  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1327  *
1328  * This function replaces all old wfMsg* functions.
1329  *
1330  * @param $key \string Message key.
1331  * Varargs: normal message parameters.
1332  * @return Message
1333  * @since 1.17
1334  */
1335 function wfMessage( $key /*...*/) {
1336         $params = func_get_args();
1337         array_shift( $params );
1338         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1339                 $params = $params[0];
1340         }
1341         return new Message( $key, $params );
1342 }
1343
1344 /**
1345  * This function accepts multiple message keys and returns a message instance
1346  * for the first message which is non-empty. If all messages are empty then an
1347  * instance of the first message key is returned.
1348  * @param varargs: message keys
1349  * @return Message
1350  * @since 1.18
1351  */
1352 function wfMessageFallback( /*...*/ ) {
1353         $args = func_get_args();
1354         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1355 }
1356
1357 /**
1358  * Get a message from anywhere, for the current user language.
1359  *
1360  * Use wfMsgForContent() instead if the message should NOT
1361  * change depending on the user preferences.
1362  *
1363  * @deprecated since 1.18
1364  *
1365  * @param string $key lookup key for the message, usually
1366  *    defined in languages/Language.php
1367  *
1368  * Parameters to the message, which can be used to insert variable text into
1369  * it, can be passed to this function in the following formats:
1370  * - One per argument, starting at the second parameter
1371  * - As an array in the second parameter
1372  * These are not shown in the function definition.
1373  *
1374  * @return String
1375  */
1376 function wfMsg( $key ) {
1377         wfDeprecated( __METHOD__, '1.21' );
1378
1379         $args = func_get_args();
1380         array_shift( $args );
1381         return wfMsgReal( $key, $args );
1382 }
1383
1384 /**
1385  * Same as above except doesn't transform the message
1386  *
1387  * @deprecated since 1.18
1388  *
1389  * @param $key String
1390  * @return String
1391  */
1392 function wfMsgNoTrans( $key ) {
1393         wfDeprecated( __METHOD__, '1.21' );
1394
1395         $args = func_get_args();
1396         array_shift( $args );
1397         return wfMsgReal( $key, $args, true, false, false );
1398 }
1399
1400 /**
1401  * Get a message from anywhere, for the current global language
1402  * set with $wgLanguageCode.
1403  *
1404  * Use this if the message should NOT change dependent on the
1405  * language set in the user's preferences. This is the case for
1406  * most text written into logs, as well as link targets (such as
1407  * the name of the copyright policy page). Link titles, on the
1408  * other hand, should be shown in the UI language.
1409  *
1410  * Note that MediaWiki allows users to change the user interface
1411  * language in their preferences, but a single installation
1412  * typically only contains content in one language.
1413  *
1414  * Be wary of this distinction: If you use wfMsg() where you should
1415  * use wfMsgForContent(), a user of the software may have to
1416  * customize potentially hundreds of messages in
1417  * order to, e.g., fix a link in every possible language.
1418  *
1419  * @deprecated since 1.18
1420  *
1421  * @param string $key lookup key for the message, usually
1422  *     defined in languages/Language.php
1423  * @return String
1424  */
1425 function wfMsgForContent( $key ) {
1426         wfDeprecated( __METHOD__, '1.21' );
1427
1428         global $wgForceUIMsgAsContentMsg;
1429         $args = func_get_args();
1430         array_shift( $args );
1431         $forcontent = true;
1432         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1433                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1434         {
1435                 $forcontent = false;
1436         }
1437         return wfMsgReal( $key, $args, true, $forcontent );
1438 }
1439
1440 /**
1441  * Same as above except doesn't transform the message
1442  *
1443  * @deprecated since 1.18
1444  *
1445  * @param $key String
1446  * @return String
1447  */
1448 function wfMsgForContentNoTrans( $key ) {
1449         wfDeprecated( __METHOD__, '1.21' );
1450
1451         global $wgForceUIMsgAsContentMsg;
1452         $args = func_get_args();
1453         array_shift( $args );
1454         $forcontent = true;
1455         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1456                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1457         {
1458                 $forcontent = false;
1459         }
1460         return wfMsgReal( $key, $args, true, $forcontent, false );
1461 }
1462
1463 /**
1464  * Really get a message
1465  *
1466  * @deprecated since 1.18
1467  *
1468  * @param string $key key to get.
1469  * @param $args
1470  * @param $useDB Boolean
1471  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1472  * @param $transform Boolean: Whether or not to transform the message.
1473  * @return String: the requested message.
1474  */
1475 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1476         wfDeprecated( __METHOD__, '1.21' );
1477
1478         wfProfileIn( __METHOD__ );
1479         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1480         $message = wfMsgReplaceArgs( $message, $args );
1481         wfProfileOut( __METHOD__ );
1482         return $message;
1483 }
1484
1485 /**
1486  * Fetch a message string value, but don't replace any keys yet.
1487  *
1488  * @deprecated since 1.18
1489  *
1490  * @param $key String
1491  * @param $useDB Bool
1492  * @param string $langCode Code of the language to get the message for, or
1493  *                  behaves as a content language switch if it is a boolean.
1494  * @param $transform Boolean: whether to parse magic words, etc.
1495  * @return string
1496  */
1497 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1498         wfDeprecated( __METHOD__, '1.21' );
1499
1500         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1501
1502         $cache = MessageCache::singleton();
1503         $message = $cache->get( $key, $useDB, $langCode );
1504         if ( $message === false ) {
1505                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1506         } elseif ( $transform ) {
1507                 $message = $cache->transform( $message );
1508         }
1509         return $message;
1510 }
1511
1512 /**
1513  * Replace message parameter keys on the given formatted output.
1514  *
1515  * @param $message String
1516  * @param $args Array
1517  * @return string
1518  * @private
1519  */
1520 function wfMsgReplaceArgs( $message, $args ) {
1521         # Fix windows line-endings
1522         # Some messages are split with explode("\n", $msg)
1523         $message = str_replace( "\r", '', $message );
1524
1525         // Replace arguments
1526         if ( count( $args ) ) {
1527                 if ( is_array( $args[0] ) ) {
1528                         $args = array_values( $args[0] );
1529                 }
1530                 $replacementKeys = array();
1531                 foreach ( $args as $n => $param ) {
1532                         $replacementKeys['$' . ( $n + 1 )] = $param;
1533                 }
1534                 $message = strtr( $message, $replacementKeys );
1535         }
1536
1537         return $message;
1538 }
1539
1540 /**
1541  * Return an HTML-escaped version of a message.
1542  * Parameter replacements, if any, are done *after* the HTML-escaping,
1543  * so parameters may contain HTML (eg links or form controls). Be sure
1544  * to pre-escape them if you really do want plaintext, or just wrap
1545  * the whole thing in htmlspecialchars().
1546  *
1547  * @deprecated since 1.18
1548  *
1549  * @param $key String
1550  * @param string ... parameters
1551  * @return string
1552  */
1553 function wfMsgHtml( $key ) {
1554         wfDeprecated( __METHOD__, '1.21' );
1555
1556         $args = func_get_args();
1557         array_shift( $args );
1558         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1559 }
1560
1561 /**
1562  * Return an HTML version of message
1563  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1564  * so parameters may contain HTML (eg links or form controls). Be sure
1565  * to pre-escape them if you really do want plaintext, or just wrap
1566  * the whole thing in htmlspecialchars().
1567  *
1568  * @deprecated since 1.18
1569  *
1570  * @param $key String
1571  * @param string ... parameters
1572  * @return string
1573  */
1574 function wfMsgWikiHtml( $key ) {
1575         wfDeprecated( __METHOD__, '1.21' );
1576
1577         $args = func_get_args();
1578         array_shift( $args );
1579         return wfMsgReplaceArgs(
1580                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1581                 /* can't be set to false */ true, /* interface */ true )->getText(),
1582                 $args );
1583 }
1584
1585 /**
1586  * Returns message in the requested format
1587  *
1588  * @deprecated since 1.18
1589  *
1590  * @param string $key key of the message
1591  * @param array $options processing rules. Can take the following options:
1592  *   <i>parse</i>: parses wikitext to HTML
1593  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1594  *       p's added by parser or tidy
1595  *   <i>escape</i>: filters message through htmlspecialchars
1596  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1597  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1598  *   <i>parsemag</i>: transform the message using magic phrases
1599  *   <i>content</i>: fetch message for content language instead of interface
1600  * Also can accept a single associative argument, of the form 'language' => 'xx':
1601  *   <i>language</i>: Language object or language code to fetch message for
1602  *       (overridden by <i>content</i>).
1603  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1604  *
1605  * @return String
1606  */
1607 function wfMsgExt( $key, $options ) {
1608         wfDeprecated( __METHOD__, '1.21' );
1609
1610         $args = func_get_args();
1611         array_shift( $args );
1612         array_shift( $args );
1613         $options = (array)$options;
1614
1615         foreach ( $options as $arrayKey => $option ) {
1616                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1617                         # An unknown index, neither numeric nor "language"
1618                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1619                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1620                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1621                 'replaceafter', 'parsemag', 'content' ) ) ) {
1622                         # A numeric index with unknown value
1623                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1624                 }
1625         }
1626
1627         if ( in_array( 'content', $options, true ) ) {
1628                 $forContent = true;
1629                 $langCode = true;
1630                 $langCodeObj = null;
1631         } elseif ( array_key_exists( 'language', $options ) ) {
1632                 $forContent = false;
1633                 $langCode = wfGetLangObj( $options['language'] );
1634                 $langCodeObj = $langCode;
1635         } else {
1636                 $forContent = false;
1637                 $langCode = false;
1638                 $langCodeObj = null;
1639         }
1640
1641         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1642
1643         if ( !in_array( 'replaceafter', $options, true ) ) {
1644                 $string = wfMsgReplaceArgs( $string, $args );
1645         }
1646
1647         $messageCache = MessageCache::singleton();
1648         $parseInline = in_array( 'parseinline', $options, true );
1649         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1650                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1651                 if ( $string instanceof ParserOutput ) {
1652                         $string = $string->getText();
1653                 }
1654
1655                 if ( $parseInline ) {
1656                         $m = array();
1657                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1658                                 $string = $m[1];
1659                         }
1660                 }
1661         } elseif ( in_array( 'parsemag', $options, true ) ) {
1662                 $string = $messageCache->transform( $string,
1663                                 !$forContent, $langCodeObj );
1664         }
1665
1666         if ( in_array( 'escape', $options, true ) ) {
1667                 $string = htmlspecialchars ( $string );
1668         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1669                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1670         }
1671
1672         if ( in_array( 'replaceafter', $options, true ) ) {
1673                 $string = wfMsgReplaceArgs( $string, $args );
1674         }
1675
1676         return $string;
1677 }
1678
1679 /**
1680  * Since wfMsg() and co suck, they don't return false if the message key they
1681  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1682  * nonexistence of messages by checking the MessageCache::get() result directly.
1683  *
1684  * @deprecated since 1.18. Use Message::isDisabled().
1685  *
1686  * @param $key      String: the message key looked up
1687  * @return Boolean True if the message *doesn't* exist.
1688  */
1689 function wfEmptyMsg( $key ) {
1690         wfDeprecated( __METHOD__, '1.21' );
1691
1692         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1693 }
1694
1695 /**
1696  * Throw a debugging exception. This function previously once exited the process,
1697  * but now throws an exception instead, with similar results.
1698  *
1699  * @param string $msg message shown when dying.
1700  * @throws MWException
1701  */
1702 function wfDebugDieBacktrace( $msg = '' ) {
1703         throw new MWException( $msg );
1704 }
1705
1706 /**
1707  * Fetch server name for use in error reporting etc.
1708  * Use real server name if available, so we know which machine
1709  * in a server farm generated the current page.
1710  *
1711  * @return string
1712  */
1713 function wfHostname() {
1714         static $host;
1715         if ( is_null( $host ) ) {
1716
1717                 # Hostname overriding
1718                 global $wgOverrideHostname;
1719                 if ( $wgOverrideHostname !== false ) {
1720                         # Set static and skip any detection
1721                         $host = $wgOverrideHostname;
1722                         return $host;
1723                 }
1724
1725                 if ( function_exists( 'posix_uname' ) ) {
1726                         // This function not present on Windows
1727                         $uname = posix_uname();
1728                 } else {
1729                         $uname = false;
1730                 }
1731                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1732                         $host = $uname['nodename'];
1733                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1734                         # Windows computer name
1735                         $host = getenv( 'COMPUTERNAME' );
1736                 } else {
1737                         # This may be a virtual server.
1738                         $host = $_SERVER['SERVER_NAME'];
1739                 }
1740         }
1741         return $host;
1742 }
1743
1744 /**
1745  * Returns a HTML comment with the elapsed time since request.
1746  * This method has no side effects.
1747  *
1748  * @return string
1749  */
1750 function wfReportTime() {
1751         global $wgRequestTime, $wgShowHostnames;
1752
1753         $elapsed = microtime( true ) - $wgRequestTime;
1754
1755         return $wgShowHostnames
1756                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1757                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1758 }
1759
1760 /**
1761  * Safety wrapper for debug_backtrace().
1762  *
1763  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1764  * murky circumstances, which may be triggered in part by stub objects
1765  * or other fancy talking'.
1766  *
1767  * Will return an empty array if Zend Optimizer is detected or if
1768  * debug_backtrace is disabled, otherwise the output from
1769  * debug_backtrace() (trimmed).
1770  *
1771  * @param int $limit This parameter can be used to limit the number of stack frames returned
1772  *
1773  * @return array of backtrace information
1774  */
1775 function wfDebugBacktrace( $limit = 0 ) {
1776         static $disabled = null;
1777
1778         if ( extension_loaded( 'Zend Optimizer' ) ) {
1779                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1780                 return array();
1781         }
1782
1783         if ( is_null( $disabled ) ) {
1784                 $disabled = false;
1785                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1786                 $functions = array_map( 'trim', $functions );
1787                 $functions = array_map( 'strtolower', $functions );
1788                 if ( in_array( 'debug_backtrace', $functions ) ) {
1789                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1790                         $disabled = true;
1791                 }
1792         }
1793         if ( $disabled ) {
1794                 return array();
1795         }
1796
1797         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1798                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1799         } else {
1800                 return array_slice( debug_backtrace(), 1 );
1801         }
1802 }
1803
1804 /**
1805  * Get a debug backtrace as a string
1806  *
1807  * @return string
1808  */
1809 function wfBacktrace() {
1810         global $wgCommandLineMode;
1811
1812         if ( $wgCommandLineMode ) {
1813                 $msg = '';
1814         } else {
1815                 $msg = "<ul>\n";
1816         }
1817         $backtrace = wfDebugBacktrace();
1818         foreach ( $backtrace as $call ) {
1819                 if ( isset( $call['file'] ) ) {
1820                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1821                         $file = $f[count( $f ) - 1];
1822                 } else {
1823                         $file = '-';
1824                 }
1825                 if ( isset( $call['line'] ) ) {
1826                         $line = $call['line'];
1827                 } else {
1828                         $line = '-';
1829                 }
1830                 if ( $wgCommandLineMode ) {
1831                         $msg .= "$file line $line calls ";
1832                 } else {
1833                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1834                 }
1835                 if ( !empty( $call['class'] ) ) {
1836                         $msg .= $call['class'] . $call['type'];
1837                 }
1838                 $msg .= $call['function'] . '()';
1839
1840                 if ( $wgCommandLineMode ) {
1841                         $msg .= "\n";
1842                 } else {
1843                         $msg .= "</li>\n";
1844                 }
1845         }
1846         if ( $wgCommandLineMode ) {
1847                 $msg .= "\n";
1848         } else {
1849                 $msg .= "</ul>\n";
1850         }
1851
1852         return $msg;
1853 }
1854
1855 /**
1856  * Get the name of the function which called this function
1857  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1858  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1859  * wfGetCaller( 3 ) is the parent of that.
1860  *
1861  * @param $level Int
1862  * @return string
1863  */
1864 function wfGetCaller( $level = 2 ) {
1865         $backtrace = wfDebugBacktrace( $level + 1 );
1866         if ( isset( $backtrace[$level] ) ) {
1867                 return wfFormatStackFrame( $backtrace[$level] );
1868         } else {
1869                 return 'unknown';
1870         }
1871 }
1872
1873 /**
1874  * Return a string consisting of callers in the stack. Useful sometimes
1875  * for profiling specific points.
1876  *
1877  * @param int $limit The maximum depth of the stack frame to return, or false for
1878  *               the entire stack.
1879  * @return String
1880  */
1881 function wfGetAllCallers( $limit = 3 ) {
1882         $trace = array_reverse( wfDebugBacktrace() );
1883         if ( !$limit || $limit > count( $trace ) - 1 ) {
1884                 $limit = count( $trace ) - 1;
1885         }
1886         $trace = array_slice( $trace, -$limit - 1, $limit );
1887         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1888 }
1889
1890 /**
1891  * Return a string representation of frame
1892  *
1893  * @param $frame Array
1894  * @return string
1895  */
1896 function wfFormatStackFrame( $frame ) {
1897         return isset( $frame['class'] ) ?
1898                 $frame['class'] . '::' . $frame['function'] :
1899                 $frame['function'];
1900 }
1901
1902 /* Some generic result counters, pulled out of SearchEngine */
1903
1904 /**
1905  * @todo document
1906  *
1907  * @param $offset Int
1908  * @param $limit Int
1909  * @return String
1910  */
1911 function wfShowingResults( $offset, $limit ) {
1912         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1913 }
1914
1915 /**
1916  * Generate (prev x| next x) (20|50|100...) type links for paging
1917  *
1918  * @param $offset String
1919  * @param $limit Integer
1920  * @param $link String
1921  * @param string $query optional URL query parameter string
1922  * @param bool $atend optional param for specified if this is the last page
1923  * @return String
1924  * @deprecated in 1.19; use Language::viewPrevNext() instead
1925  */
1926 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1927         wfDeprecated( __METHOD__, '1.19' );
1928
1929         global $wgLang;
1930
1931         $query = wfCgiToArray( $query );
1932
1933         if ( is_object( $link ) ) {
1934                 $title = $link;
1935         } else {
1936                 $title = Title::newFromText( $link );
1937                 if ( is_null( $title ) ) {
1938                         return false;
1939                 }
1940         }
1941
1942         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1943 }
1944
1945 /**
1946  * Make a list item, used by various special pages
1947  *
1948  * @param string $page Page link
1949  * @param string $details Text between brackets
1950  * @param $oppositedm Boolean   Add the direction mark opposite to your
1951  *                                                              language, to display text properly
1952  * @return String
1953  * @deprecated since 1.19; use Language::specialList() instead
1954  */
1955 function wfSpecialList( $page, $details, $oppositedm = true ) {
1956         wfDeprecated( __METHOD__, '1.19' );
1957
1958         global $wgLang;
1959         return $wgLang->specialList( $page, $details, $oppositedm );
1960 }
1961
1962 /**
1963  * @todo document
1964  * @todo FIXME: We may want to blacklist some broken browsers
1965  *
1966  * @param $force Bool
1967  * @return bool Whereas client accept gzip compression
1968  */
1969 function wfClientAcceptsGzip( $force = false ) {
1970         static $result = null;
1971         if ( $result === null || $force ) {
1972                 $result = false;
1973                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1974                         # @todo FIXME: We may want to blacklist some broken browsers
1975                         $m = array();
1976                         if ( preg_match(
1977                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1978                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1979                                 $m )
1980                         )
1981                         {
1982                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1983                                         $result = false;
1984                                         return $result;
1985                                 }
1986                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1987                                 $result = true;
1988                         }
1989                 }
1990         }
1991         return $result;
1992 }
1993
1994 /**
1995  * Obtain the offset and limit values from the request string;
1996  * used in special pages
1997  *
1998  * @param int $deflimit default limit if none supplied
1999  * @param string $optionname Name of a user preference to check against
2000  * @return array
2001  *
2002  */
2003 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2004         global $wgRequest;
2005         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2006 }
2007
2008 /**
2009  * Escapes the given text so that it may be output using addWikiText()
2010  * without any linking, formatting, etc. making its way through. This
2011  * is achieved by substituting certain characters with HTML entities.
2012  * As required by the callers, "<nowiki>" is not used.
2013  *
2014  * @param string $text text to be escaped
2015  * @return String
2016  */
2017 function wfEscapeWikiText( $text ) {
2018         $text = strtr( "\n$text", array(
2019                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2020                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2021                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2022                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2023                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2024                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2025         ) );
2026         return substr( $text, 1 );
2027 }
2028
2029 /**
2030  * Get the current unix timestamp with microseconds.  Useful for profiling
2031  * @deprecated since 1.22; call microtime() directly
2032  * @return Float
2033  */
2034 function wfTime() {
2035         wfDeprecated( __FUNCTION__, '1.22' );
2036         return microtime( true );
2037 }
2038
2039 /**
2040  * Sets dest to source and returns the original value of dest
2041  * If source is NULL, it just returns the value, it doesn't set the variable
2042  * If force is true, it will set the value even if source is NULL
2043  *
2044  * @param $dest Mixed
2045  * @param $source Mixed
2046  * @param $force Bool
2047  * @return Mixed
2048  */
2049 function wfSetVar( &$dest, $source, $force = false ) {
2050         $temp = $dest;
2051         if ( !is_null( $source ) || $force ) {
2052                 $dest = $source;
2053         }
2054         return $temp;
2055 }
2056
2057 /**
2058  * As for wfSetVar except setting a bit
2059  *
2060  * @param $dest Int
2061  * @param $bit Int
2062  * @param $state Bool
2063  *
2064  * @return bool
2065  */
2066 function wfSetBit( &$dest, $bit, $state = true ) {
2067         $temp = (bool)( $dest & $bit );
2068         if ( !is_null( $state ) ) {
2069                 if ( $state ) {
2070                         $dest |= $bit;
2071                 } else {
2072                         $dest &= ~$bit;
2073                 }
2074         }
2075         return $temp;
2076 }
2077
2078 /**
2079  * A wrapper around the PHP function var_export().
2080  * Either print it or add it to the regular output ($wgOut).
2081  *
2082  * @param $var mixed A PHP variable to dump.
2083  */
2084 function wfVarDump( $var ) {
2085         global $wgOut;
2086         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2087         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2088                 print $s;
2089         } else {
2090                 $wgOut->addHTML( $s );
2091         }
2092 }
2093
2094 /**
2095  * Provide a simple HTTP error.
2096  *
2097  * @param $code Int|String
2098  * @param $label String
2099  * @param $desc String
2100  */
2101 function wfHttpError( $code, $label, $desc ) {
2102         global $wgOut;
2103         $wgOut->disable();
2104         header( "HTTP/1.0 $code $label" );
2105         header( "Status: $code $label" );
2106         $wgOut->sendCacheControl();
2107
2108         header( 'Content-type: text/html; charset=utf-8' );
2109         print "<!doctype html>" .
2110                 '<html><head><title>' .
2111                 htmlspecialchars( $label ) .
2112                 '</title></head><body><h1>' .
2113                 htmlspecialchars( $label ) .
2114                 '</h1><p>' .
2115                 nl2br( htmlspecialchars( $desc ) ) .
2116                 "</p></body></html>\n";
2117 }
2118
2119 /**
2120  * Clear away any user-level output buffers, discarding contents.
2121  *
2122  * Suitable for 'starting afresh', for instance when streaming
2123  * relatively large amounts of data without buffering, or wanting to
2124  * output image files without ob_gzhandler's compression.
2125  *
2126  * The optional $resetGzipEncoding parameter controls suppression of
2127  * the Content-Encoding header sent by ob_gzhandler; by default it
2128  * is left. See comments for wfClearOutputBuffers() for why it would
2129  * be used.
2130  *
2131  * Note that some PHP configuration options may add output buffer
2132  * layers which cannot be removed; these are left in place.
2133  *
2134  * @param $resetGzipEncoding Bool
2135  */
2136 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2137         if ( $resetGzipEncoding ) {
2138                 // Suppress Content-Encoding and Content-Length
2139                 // headers from 1.10+s wfOutputHandler
2140                 global $wgDisableOutputCompression;
2141                 $wgDisableOutputCompression = true;
2142         }
2143         while ( $status = ob_get_status() ) {
2144                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2145                         // Probably from zlib.output_compression or other
2146                         // PHP-internal setting which can't be removed.
2147                         //
2148                         // Give up, and hope the result doesn't break
2149                         // output behavior.
2150                         break;
2151                 }
2152                 if ( !ob_end_clean() ) {
2153                         // Could not remove output buffer handler; abort now
2154                         // to avoid getting in some kind of infinite loop.
2155                         break;
2156                 }
2157                 if ( $resetGzipEncoding ) {
2158                         if ( $status['name'] == 'ob_gzhandler' ) {
2159                                 // Reset the 'Content-Encoding' field set by this handler
2160                                 // so we can start fresh.
2161                                 header_remove( 'Content-Encoding' );
2162                                 break;
2163                         }
2164                 }
2165         }
2166 }
2167
2168 /**
2169  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2170  *
2171  * Clear away output buffers, but keep the Content-Encoding header
2172  * produced by ob_gzhandler, if any.
2173  *
2174  * This should be used for HTTP 304 responses, where you need to
2175  * preserve the Content-Encoding header of the real result, but
2176  * also need to suppress the output of ob_gzhandler to keep to spec
2177  * and avoid breaking Firefox in rare cases where the headers and
2178  * body are broken over two packets.
2179  */
2180 function wfClearOutputBuffers() {
2181         wfResetOutputBuffers( false );
2182 }
2183
2184 /**
2185  * Converts an Accept-* header into an array mapping string values to quality
2186  * factors
2187  *
2188  * @param $accept String
2189  * @param string $def default
2190  * @return Array
2191  */
2192 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2193         # No arg means accept anything (per HTTP spec)
2194         if ( !$accept ) {
2195                 return array( $def => 1.0 );
2196         }
2197
2198         $prefs = array();
2199
2200         $parts = explode( ',', $accept );
2201
2202         foreach ( $parts as $part ) {
2203                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2204                 $values = explode( ';', trim( $part ) );
2205                 $match = array();
2206                 if ( count( $values ) == 1 ) {
2207                         $prefs[$values[0]] = 1.0;
2208                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2209                         $prefs[$values[0]] = floatval( $match[1] );
2210                 }
2211         }
2212
2213         return $prefs;
2214 }
2215
2216 /**
2217  * Checks if a given MIME type matches any of the keys in the given
2218  * array. Basic wildcards are accepted in the array keys.
2219  *
2220  * Returns the matching MIME type (or wildcard) if a match, otherwise
2221  * NULL if no match.
2222  *
2223  * @param $type String
2224  * @param $avail Array
2225  * @return string
2226  * @private
2227  */
2228 function mimeTypeMatch( $type, $avail ) {
2229         if ( array_key_exists( $type, $avail ) ) {
2230                 return $type;
2231         } else {
2232                 $parts = explode( '/', $type );
2233                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2234                         return $parts[0] . '/*';
2235                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2236                         return '*/*';
2237                 } else {
2238                         return null;
2239                 }
2240         }
2241 }
2242
2243 /**
2244  * Returns the 'best' match between a client's requested internet media types
2245  * and the server's list of available types. Each list should be an associative
2246  * array of type to preference (preference is a float between 0.0 and 1.0).
2247  * Wildcards in the types are acceptable.
2248  *
2249  * @param array $cprefs client's acceptable type list
2250  * @param array $sprefs server's offered types
2251  * @return string
2252  *
2253  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2254  * XXX: generalize to negotiate other stuff
2255  */
2256 function wfNegotiateType( $cprefs, $sprefs ) {
2257         $combine = array();
2258
2259         foreach ( array_keys( $sprefs ) as $type ) {
2260                 $parts = explode( '/', $type );
2261                 if ( $parts[1] != '*' ) {
2262                         $ckey = mimeTypeMatch( $type, $cprefs );
2263                         if ( $ckey ) {
2264                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2265                         }
2266                 }
2267         }
2268
2269         foreach ( array_keys( $cprefs ) as $type ) {
2270                 $parts = explode( '/', $type );
2271                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2272                         $skey = mimeTypeMatch( $type, $sprefs );
2273                         if ( $skey ) {
2274                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2275                         }
2276                 }
2277         }
2278
2279         $bestq = 0;
2280         $besttype = null;
2281
2282         foreach ( array_keys( $combine ) as $type ) {
2283                 if ( $combine[$type] > $bestq ) {
2284                         $besttype = $type;
2285                         $bestq = $combine[$type];
2286                 }
2287         }
2288
2289         return $besttype;
2290 }
2291
2292 /**
2293  * Reference-counted warning suppression
2294  *
2295  * @param $end Bool
2296  */
2297 function wfSuppressWarnings( $end = false ) {
2298         static $suppressCount = 0;
2299         static $originalLevel = false;
2300
2301         if ( $end ) {
2302                 if ( $suppressCount ) {
2303                         --$suppressCount;
2304                         if ( !$suppressCount ) {
2305                                 error_reporting( $originalLevel );
2306                         }
2307                 }
2308         } else {
2309                 if ( !$suppressCount ) {
2310                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2311                 }
2312                 ++$suppressCount;
2313         }
2314 }
2315
2316 /**
2317  * Restore error level to previous value
2318  */
2319 function wfRestoreWarnings() {
2320         wfSuppressWarnings( true );
2321 }
2322
2323 # Autodetect, convert and provide timestamps of various types
2324
2325 /**
2326  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2327  */
2328 define( 'TS_UNIX', 0 );
2329
2330 /**
2331  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2332  */
2333 define( 'TS_MW', 1 );
2334
2335 /**
2336  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2337  */
2338 define( 'TS_DB', 2 );
2339
2340 /**
2341  * RFC 2822 format, for E-mail and HTTP headers
2342  */
2343 define( 'TS_RFC2822', 3 );
2344
2345 /**
2346  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2347  *
2348  * This is used by Special:Export
2349  */
2350 define( 'TS_ISO_8601', 4 );
2351
2352 /**
2353  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2354  *
2355  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2356  *       DateTime tag and page 36 for the DateTimeOriginal and
2357  *       DateTimeDigitized tags.
2358  */
2359 define( 'TS_EXIF', 5 );
2360
2361 /**
2362  * Oracle format time.
2363  */
2364 define( 'TS_ORACLE', 6 );
2365
2366 /**
2367  * Postgres format time.
2368  */
2369 define( 'TS_POSTGRES', 7 );
2370
2371 /**
2372  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2373  */
2374 define( 'TS_ISO_8601_BASIC', 9 );
2375
2376 /**
2377  * Get a timestamp string in one of various formats
2378  *
2379  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2380  *                    function will autodetect which format is supplied and act
2381  *                    accordingly.
2382  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2383  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2384  */
2385 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2386         try {
2387                 $timestamp = new MWTimestamp( $ts );
2388                 return $timestamp->getTimestamp( $outputtype );
2389         } catch ( TimestampException $e ) {
2390                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2391                 return false;
2392         }
2393 }
2394
2395 /**
2396  * Return a formatted timestamp, or null if input is null.
2397  * For dealing with nullable timestamp columns in the database.
2398  *
2399  * @param $outputtype Integer
2400  * @param $ts String
2401  * @return String
2402  */
2403 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2404         if ( is_null( $ts ) ) {
2405                 return null;
2406         } else {
2407                 return wfTimestamp( $outputtype, $ts );
2408         }
2409 }
2410
2411 /**
2412  * Convenience function; returns MediaWiki timestamp for the present time.
2413  *
2414  * @return string
2415  */
2416 function wfTimestampNow() {
2417         # return NOW
2418         return wfTimestamp( TS_MW, time() );
2419 }
2420
2421 /**
2422  * Check if the operating system is Windows
2423  *
2424  * @return Bool: true if it's Windows, False otherwise.
2425  */
2426 function wfIsWindows() {
2427         static $isWindows = null;
2428         if ( $isWindows === null ) {
2429                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2430         }
2431         return $isWindows;
2432 }
2433
2434 /**
2435  * Check if we are running under HipHop
2436  *
2437  * @return Bool
2438  */
2439 function wfIsHipHop() {
2440         return function_exists( 'hphp_thread_set_warmup_enabled' );
2441 }
2442
2443 /**
2444  * Swap two variables
2445  *
2446  * @param $x Mixed
2447  * @param $y Mixed
2448  */
2449 function swap( &$x, &$y ) {
2450         $z = $x;
2451         $x = $y;
2452         $y = $z;
2453 }
2454
2455 /**
2456  * Tries to get the system directory for temporary files. First
2457  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2458  * environment variables are then checked in sequence, and if none are
2459  * set try sys_get_temp_dir().
2460  *
2461  * NOTE: When possible, use instead the tmpfile() function to create
2462  * temporary files to avoid race conditions on file creation, etc.
2463  *
2464  * @return String
2465  */
2466 function wfTempDir() {
2467         global $wgTmpDirectory;
2468
2469         if ( $wgTmpDirectory !== false ) {
2470                 return $wgTmpDirectory;
2471         }
2472
2473         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2474
2475         foreach ( $tmpDir as $tmp ) {
2476                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2477                         return $tmp;
2478                 }
2479         }
2480         return sys_get_temp_dir();
2481 }
2482
2483 /**
2484  * Make directory, and make all parent directories if they don't exist
2485  *
2486  * @param string $dir full path to directory to create
2487  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2488  * @param string $caller optional caller param for debugging.
2489  * @throws MWException
2490  * @return bool
2491  */
2492 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2493         global $wgDirectoryMode;
2494
2495         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2496                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2497         }
2498
2499         if ( !is_null( $caller ) ) {
2500                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2501         }
2502
2503         if ( strval( $dir ) === '' || file_exists( $dir ) ) {
2504                 return true;
2505         }
2506
2507         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2508
2509         if ( is_null( $mode ) ) {
2510                 $mode = $wgDirectoryMode;
2511         }
2512
2513         // Turn off the normal warning, we're doing our own below
2514         wfSuppressWarnings();
2515         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2516         wfRestoreWarnings();
2517
2518         if ( !$ok ) {
2519                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2520                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2521         }
2522         return $ok;
2523 }
2524
2525 /**
2526  * Remove a directory and all its content.
2527  * Does not hide error.
2528  */
2529 function wfRecursiveRemoveDir( $dir ) {
2530         wfDebug( __FUNCTION__ . "( $dir )\n" );
2531         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2532         if ( is_dir( $dir ) ) {
2533                 $objects = scandir( $dir );
2534                 foreach ( $objects as $object ) {
2535                         if ( $object != "." && $object != ".." ) {
2536                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2537                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2538                                 } else {
2539                                         unlink( $dir . '/' . $object );
2540                                 }
2541                         }
2542                 }
2543                 reset( $objects );
2544                 rmdir( $dir );
2545         }
2546 }
2547
2548 /**
2549  * @param $nr Mixed: the number to format
2550  * @param $acc Integer: the number of digits after the decimal point, default 2
2551  * @param $round Boolean: whether or not to round the value, default true
2552  * @return float
2553  */
2554 function wfPercent( $nr, $acc = 2, $round = true ) {
2555         $ret = sprintf( "%.${acc}f", $nr );
2556         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2557 }
2558
2559 /**
2560  * Find out whether or not a mixed variable exists in a string
2561  *
2562  * @deprecated Just use str(i)pos
2563  * @param $needle String
2564  * @param $str String
2565  * @param $insensitive Boolean
2566  * @return Boolean
2567  */
2568 function in_string( $needle, $str, $insensitive = false ) {
2569         wfDeprecated( __METHOD__, '1.21' );
2570         $func = 'strpos';
2571         if ( $insensitive ) {
2572                 $func = 'stripos';
2573         }
2574
2575         return $func( $str, $needle ) !== false;
2576 }
2577
2578 /**
2579  * Safety wrapper around ini_get() for boolean settings.
2580  * The values returned from ini_get() are pre-normalized for settings
2581  * set via php.ini or php_flag/php_admin_flag... but *not*
2582  * for those set via php_value/php_admin_value.
2583  *
2584  * It's fairly common for people to use php_value instead of php_flag,
2585  * which can leave you with an 'off' setting giving a false positive
2586  * for code that just takes the ini_get() return value as a boolean.
2587  *
2588  * To make things extra interesting, setting via php_value accepts
2589  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2590  * Unrecognized values go false... again opposite PHP's own coercion
2591  * from string to bool.
2592  *
2593  * Luckily, 'properly' set settings will always come back as '0' or '1',
2594  * so we only have to worry about them and the 'improper' settings.
2595  *
2596  * I frickin' hate PHP... :P
2597  *
2598  * @param $setting String
2599  * @return Bool
2600  */
2601 function wfIniGetBool( $setting ) {
2602         $val = strtolower( ini_get( $setting ) );
2603         // 'on' and 'true' can't have whitespace around them, but '1' can.
2604         return $val == 'on'
2605                 || $val == 'true'
2606                 || $val == 'yes'
2607                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2608 }
2609
2610 /**
2611  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2612  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2613  *
2614  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2615  *                          should be omitted
2616  * @param string $fileName Name of the library, if not $extension.suffix
2617  * @return Bool - Whether or not the extension is loaded
2618  */
2619 function wfDl( $extension, $fileName = null ) {
2620         if ( extension_loaded( $extension ) ) {
2621                 return true;
2622         }
2623
2624         $canDl = false;
2625         if ( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2626                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2627                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2628         }
2629
2630         if ( $canDl ) {
2631                 $fileName = $fileName ? $fileName : $extension;
2632                 if ( wfIsWindows() ) {
2633                         $fileName = 'php_' . $fileName;
2634                 }
2635                 wfSuppressWarnings();
2636                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2637                 wfRestoreWarnings();
2638         }
2639         return extension_loaded( $extension );
2640 }
2641
2642 /**
2643  * Windows-compatible version of escapeshellarg()
2644  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2645  * function puts single quotes in regardless of OS.
2646  *
2647  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2648  * earlier distro releases of PHP)
2649  *
2650  * @param varargs
2651  * @return String
2652  */
2653 function wfEscapeShellArg() {
2654         wfInitShellLocale();
2655
2656         $args = func_get_args();
2657         $first = true;
2658         $retVal = '';
2659         foreach ( $args as $arg ) {
2660                 if ( !$first ) {
2661                         $retVal .= ' ';
2662                 } else {
2663                         $first = false;
2664                 }
2665
2666                 if ( wfIsWindows() ) {
2667                         // Escaping for an MSVC-style command line parser and CMD.EXE
2668                         // Refs:
2669                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2670                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2671                         //  * Bug #13518
2672                         //  * CR r63214
2673                         // Double the backslashes before any double quotes. Escape the double quotes.
2674                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2675                         $arg = '';
2676                         $iteration = 0;
2677                         foreach ( $tokens as $token ) {
2678                                 if ( $iteration % 2 == 1 ) {
2679                                         // Delimiter, a double quote preceded by zero or more slashes
2680                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2681                                 } elseif ( $iteration % 4 == 2 ) {
2682                                         // ^ in $token will be outside quotes, need to be escaped
2683                                         $arg .= str_replace( '^', '^^', $token );
2684                                 } else { // $iteration % 4 == 0
2685                                         // ^ in $token will appear inside double quotes, so leave as is
2686                                         $arg .= $token;
2687                                 }
2688                                 $iteration++;
2689                         }
2690                         // Double the backslashes before the end of the string, because
2691                         // we will soon add a quote
2692                         $m = array();
2693                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2694                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2695                         }
2696
2697                         // Add surrounding quotes
2698                         $retVal .= '"' . $arg . '"';
2699                 } else {
2700                         $retVal .= escapeshellarg( $arg );
2701                 }
2702         }
2703         return $retVal;
2704 }
2705
2706 /**
2707  * Check if wfShellExec() is effectively disabled via php.ini config
2708  * @return bool|string False or one of (safemode,disabled)
2709  * @since 1.22
2710  */
2711 function wfShellExecDisabled() {
2712         static $disabled = null;
2713         if ( is_null( $disabled ) ) {
2714                 $disabled = false;
2715                 if ( wfIniGetBool( 'safe_mode' ) ) {
2716                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2717                         $disabled = 'safemode';
2718                 } else {
2719                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2720                         $functions = array_map( 'trim', $functions );
2721                         $functions = array_map( 'strtolower', $functions );
2722                         if ( in_array( 'passthru', $functions ) ) {
2723                                 wfDebug( "passthru is in disabled_functions\n" );
2724                                 $disabled = 'passthru';
2725                         }
2726                 }
2727         }
2728         return $disabled;
2729 }
2730
2731 /**
2732  * Execute a shell command, with time and memory limits mirrored from the PHP
2733  * configuration if supported.
2734  * @param string $cmd Command line, properly escaped for shell.
2735  * @param &$retval null|Mixed optional, will receive the program's exit code.
2736  *                 (non-zero is usually failure)
2737  * @param array $environ optional environment variables which should be
2738  *                 added to the executed command environment.
2739  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2740  *                 this overwrites the global wgShellMax* limits.
2741  * @return string collected stdout as a string (trailing newlines stripped)
2742  */
2743 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2744         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2745                 $wgMaxShellWallClockTime, $wgShellCgroup;
2746
2747         $disabled = wfShellExecDisabled();
2748         if ( $disabled ) {
2749                 $retval = 1;
2750                 return $disabled == 'safemode' ?
2751                         'Unable to run external programs in safe mode.' :
2752                         'Unable to run external programs, passthru() is disabled.';
2753         }
2754
2755         wfInitShellLocale();
2756
2757         $envcmd = '';
2758         foreach ( $environ as $k => $v ) {
2759                 if ( wfIsWindows() ) {
2760                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2761                          * appear in the environment variable, so we must use carat escaping as documented in
2762                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2763                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2764                          * are listed there but doesn't appear to need it.
2765                          */
2766                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2767                 } else {
2768                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2769                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2770                          */
2771                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2772                 }
2773         }
2774         $cmd = $envcmd . $cmd;
2775
2776         if ( php_uname( 's' ) == 'Linux' ) {
2777                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2778                 if ( isset( $limits['walltime'] ) ) {
2779                         $wallTime = intval( $limits['walltime'] );
2780                 } elseif ( isset( $limits['time'] ) ) {
2781                         $wallTime = $time;
2782                 } else {
2783                         $wallTime = intval( $wgMaxShellWallClockTime );
2784                 }
2785                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2786                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2787
2788                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2789                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2790                                 escapeshellarg( $cmd ) . ' ' .
2791                                 escapeshellarg(
2792                                         "MW_CPU_LIMIT=$time; " .
2793                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2794                                         "MW_MEM_LIMIT=$mem; " .
2795                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2796                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2797                                 );
2798                 }
2799         }
2800         wfDebug( "wfShellExec: $cmd\n" );
2801
2802         $retval = 1; // error by default?
2803         ob_start();
2804         passthru( $cmd, $retval );
2805         $output = ob_get_contents();
2806         ob_end_clean();
2807
2808         if ( $retval == 127 ) {
2809                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2810         }
2811         return $output;
2812 }
2813
2814 /**
2815  * Workaround for http://bugs.php.net/bug.php?id=45132
2816  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2817  */
2818 function wfInitShellLocale() {
2819         static $done = false;
2820         if ( $done ) {
2821                 return;
2822         }
2823         $done = true;
2824         global $wgShellLocale;
2825         if ( !wfIniGetBool( 'safe_mode' ) ) {
2826                 putenv( "LC_CTYPE=$wgShellLocale" );
2827                 setlocale( LC_CTYPE, $wgShellLocale );
2828         }
2829 }
2830
2831 /**
2832  * Alias to wfShellWikiCmd()
2833  * @see wfShellWikiCmd()
2834  */
2835 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2836         return wfShellWikiCmd( $script, $parameters, $options );
2837 }
2838
2839 /**
2840  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2841  * Note that $parameters should be a flat array and an option with an argument
2842  * should consist of two consecutive items in the array (do not use "--option value").
2843  * @param string $script MediaWiki cli script path
2844  * @param array $parameters Arguments and options to the script
2845  * @param array $options Associative array of options:
2846  *              'php': The path to the php executable
2847  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2848  * @return Array
2849  */
2850 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2851         global $wgPhpCli;
2852         // Give site config file a chance to run the script in a wrapper.
2853         // The caller may likely want to call wfBasename() on $script.
2854         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2855         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2856         if ( isset( $options['wrapper'] ) ) {
2857                 $cmd[] = $options['wrapper'];
2858         }
2859         $cmd[] = $script;
2860         // Escape each parameter for shell
2861         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2862 }
2863
2864 /**
2865  * wfMerge attempts to merge differences between three texts.
2866  * Returns true for a clean merge and false for failure or a conflict.
2867  *
2868  * @param $old String
2869  * @param $mine String
2870  * @param $yours String
2871  * @param $result String
2872  * @return Bool
2873  */
2874 function wfMerge( $old, $mine, $yours, &$result ) {
2875         global $wgDiff3;
2876
2877         # This check may also protect against code injection in
2878         # case of broken installations.
2879         wfSuppressWarnings();
2880         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2881         wfRestoreWarnings();
2882
2883         if ( !$haveDiff3 ) {
2884                 wfDebug( "diff3 not found\n" );
2885                 return false;
2886         }
2887
2888         # Make temporary files
2889         $td = wfTempDir();
2890         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2891         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2892         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2893
2894         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2895         #       a newline character. To avoid this, we normalize the trailing whitespace before
2896         #       creating the diff.
2897
2898         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2899         fclose( $oldtextFile );
2900         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2901         fclose( $mytextFile );
2902         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2903         fclose( $yourtextFile );
2904
2905         # Check for a conflict
2906         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2907                 wfEscapeShellArg( $mytextName ) . ' ' .
2908                 wfEscapeShellArg( $oldtextName ) . ' ' .
2909                 wfEscapeShellArg( $yourtextName );
2910         $handle = popen( $cmd, 'r' );
2911
2912         if ( fgets( $handle, 1024 ) ) {
2913                 $conflict = true;
2914         } else {
2915                 $conflict = false;
2916         }
2917         pclose( $handle );
2918
2919         # Merge differences
2920         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2921                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2922         $handle = popen( $cmd, 'r' );
2923         $result = '';
2924         do {
2925                 $data = fread( $handle, 8192 );
2926                 if ( strlen( $data ) == 0 ) {
2927                         break;
2928                 }
2929                 $result .= $data;
2930         } while ( true );
2931         pclose( $handle );
2932         unlink( $mytextName );
2933         unlink( $oldtextName );
2934         unlink( $yourtextName );
2935
2936         if ( $result === '' && $old !== '' && !$conflict ) {
2937                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2938                 $conflict = true;
2939         }
2940         return !$conflict;
2941 }
2942
2943 /**
2944  * Returns unified plain-text diff of two texts.
2945  * Useful for machine processing of diffs.
2946  *
2947  * @param string $before the text before the changes.
2948  * @param string $after the text after the changes.
2949  * @param string $params command-line options for the diff command.
2950  * @return String: unified diff of $before and $after
2951  */
2952 function wfDiff( $before, $after, $params = '-u' ) {
2953         if ( $before == $after ) {
2954                 return '';
2955         }
2956
2957         global $wgDiff;
2958         wfSuppressWarnings();
2959         $haveDiff = $wgDiff && file_exists( $wgDiff );
2960         wfRestoreWarnings();
2961
2962         # This check may also protect against code injection in
2963         # case of broken installations.
2964         if ( !$haveDiff ) {
2965                 wfDebug( "diff executable not found\n" );
2966                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2967                 $format = new UnifiedDiffFormatter();
2968                 return $format->format( $diffs );
2969         }
2970
2971         # Make temporary files
2972         $td = wfTempDir();
2973         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2974         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2975
2976         fwrite( $oldtextFile, $before );
2977         fclose( $oldtextFile );
2978         fwrite( $newtextFile, $after );
2979         fclose( $newtextFile );
2980
2981         // Get the diff of the two files
2982         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2983
2984         $h = popen( $cmd, 'r' );
2985
2986         $diff = '';
2987
2988         do {
2989                 $data = fread( $h, 8192 );
2990                 if ( strlen( $data ) == 0 ) {
2991                         break;
2992                 }
2993                 $diff .= $data;
2994         } while ( true );
2995
2996         // Clean up
2997         pclose( $h );
2998         unlink( $oldtextName );
2999         unlink( $newtextName );
3000
3001         // Kill the --- and +++ lines. They're not useful.
3002         $diff_lines = explode( "\n", $diff );
3003         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3004                 unset( $diff_lines[0] );
3005         }
3006         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3007                 unset( $diff_lines[1] );
3008         }
3009
3010         $diff = implode( "\n", $diff_lines );
3011
3012         return $diff;
3013 }
3014
3015 /**
3016  * This function works like "use VERSION" in Perl, the program will die with a
3017  * backtrace if the current version of PHP is less than the version provided
3018  *
3019  * This is useful for extensions which due to their nature are not kept in sync
3020  * with releases, and might depend on other versions of PHP than the main code
3021  *
3022  * Note: PHP might die due to parsing errors in some cases before it ever
3023  *       manages to call this function, such is life
3024  *
3025  * @see perldoc -f use
3026  *
3027  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3028  *                 a float
3029  * @throws MWException
3030  */
3031 function wfUsePHP( $req_ver ) {
3032         $php_ver = PHP_VERSION;
3033
3034         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3035                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3036         }
3037 }
3038
3039 /**
3040  * This function works like "use VERSION" in Perl except it checks the version
3041  * of MediaWiki, the program will die with a backtrace if the current version
3042  * of MediaWiki is less than the version provided.
3043  *
3044  * This is useful for extensions which due to their nature are not kept in sync
3045  * with releases
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 wfUseMW( $req_ver ) {
3054         global $wgVersion;
3055
3056         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3057                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3058         }
3059 }
3060
3061 /**
3062  * Return the final portion of a pathname.
3063  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3064  * http://bugs.php.net/bug.php?id=33898
3065  *
3066  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3067  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3068  *
3069  * @param $path String
3070  * @param string $suffix to remove if present
3071  * @return String
3072  */
3073 function wfBaseName( $path, $suffix = '' ) {
3074         $encSuffix = ( $suffix == '' )
3075                 ? ''
3076                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3077         $matches = array();
3078         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3079                 return $matches[1];
3080         } else {
3081                 return '';
3082         }
3083 }
3084
3085 /**
3086  * Generate a relative path name to the given file.
3087  * May explode on non-matching case-insensitive paths,
3088  * funky symlinks, etc.
3089  *
3090  * @param string $path absolute destination path including target filename
3091  * @param string $from Absolute source path, directory only
3092  * @return String
3093  */
3094 function wfRelativePath( $path, $from ) {
3095         // Normalize mixed input on Windows...
3096         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3097         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3098
3099         // Trim trailing slashes -- fix for drive root
3100         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3101         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3102
3103         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3104         $against = explode( DIRECTORY_SEPARATOR, $from );
3105
3106         if ( $pieces[0] !== $against[0] ) {
3107                 // Non-matching Windows drive letters?
3108                 // Return a full path.
3109                 return $path;
3110         }
3111
3112         // Trim off common prefix
3113         while ( count( $pieces ) && count( $against )
3114                 && $pieces[0] == $against[0] ) {
3115                 array_shift( $pieces );
3116                 array_shift( $against );
3117         }
3118
3119         // relative dots to bump us to the parent
3120         while ( count( $against ) ) {
3121                 array_unshift( $pieces, '..' );
3122                 array_shift( $against );
3123         }
3124
3125         array_push( $pieces, wfBaseName( $path ) );
3126
3127         return implode( DIRECTORY_SEPARATOR, $pieces );
3128 }
3129
3130 /**
3131  * Do any deferred updates and clear the list
3132  *
3133  * @deprecated since 1.19
3134  * @see DeferredUpdates::doUpdate()
3135  * @param $commit string
3136  */
3137 function wfDoUpdates( $commit = '' ) {
3138         wfDeprecated( __METHOD__, '1.19' );
3139         DeferredUpdates::doUpdates( $commit );
3140 }
3141
3142 /**
3143  * Convert an arbitrarily-long digit string from one numeric base
3144  * to another, optionally zero-padding to a minimum column width.
3145  *
3146  * Supports base 2 through 36; digit values 10-36 are represented
3147  * as lowercase letters a-z. Input is case-insensitive.
3148  *
3149  * @param string $input Input number
3150  * @param int $sourceBase Base of the input number
3151  * @param int $destBase Desired base of the output
3152  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3153  * @param bool $lowercase Whether to output in lowercase or uppercase
3154  * @param string $engine Either "gmp", "bcmath", or "php"
3155  * @return string|bool The output number as a string, or false on error
3156  */
3157 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3158         $input = (string)$input;
3159         if (
3160                 $sourceBase < 2 ||
3161                 $sourceBase > 36 ||
3162                 $destBase < 2 ||
3163                 $destBase > 36 ||
3164                 $sourceBase != (int) $sourceBase ||
3165                 $destBase != (int) $destBase ||
3166                 $pad != (int) $pad ||
3167                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3168         ) {
3169                 return false;
3170         }
3171
3172         static $baseChars = array(
3173                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3174                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3175                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3176                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3177                 34 => 'y', 35 => 'z',
3178
3179                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3180                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3181                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3182                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3183                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3184                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3185         );
3186
3187         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3188                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3189         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3190                 $decimal = '0';
3191                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3192                         $decimal = bcmul( $decimal, $sourceBase );
3193                         $decimal = bcadd( $decimal, $baseChars[$char] );
3194                 }
3195
3196                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3197                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3198                 }
3199
3200                 $result = strrev( $result );
3201         } else {
3202                 $inDigits = array();
3203                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3204                         $inDigits[] = $baseChars[$char];
3205                 }
3206
3207                 // Iterate over the input, modulo-ing out an output digit
3208                 // at a time until input is gone.
3209                 $result = '';
3210                 while ( $inDigits ) {
3211                         $work = 0;
3212                         $workDigits = array();
3213
3214                         // Long division...
3215                         foreach ( $inDigits as $digit ) {
3216                                 $work *= $sourceBase;
3217                                 $work += $digit;
3218
3219                                 if ( $workDigits || $work >= $destBase ) {
3220                                         $workDigits[] = (int) ( $work / $destBase );
3221                                 }
3222                                 $work %= $destBase;
3223                         }
3224
3225                         // All that division leaves us with a remainder,
3226                         // which is conveniently our next output digit.
3227                         $result .= $baseChars[$work];
3228
3229                         // And we continue!
3230                         $inDigits = $workDigits;
3231                 }
3232
3233                 $result = strrev( $result );
3234         }
3235
3236         if ( !$lowercase ) {
3237                 $result = strtoupper( $result );
3238         }
3239
3240         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3241 }
3242
3243 /**
3244  * Create an object with a given name and an array of construct parameters
3245  *
3246  * @param $name String
3247  * @param array $p parameters
3248  * @return object
3249  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3250  */
3251 function wfCreateObject( $name, $p ) {
3252         wfDeprecated( __FUNCTION__, '1.18' );
3253         return MWFunction::newObj( $name, $p );
3254 }
3255
3256 /**
3257  * @return bool
3258  */
3259 function wfHttpOnlySafe() {
3260         global $wgHttpOnlyBlacklist;
3261
3262         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3263                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3264                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3265                                 return false;
3266                         }
3267                 }
3268         }
3269
3270         return true;
3271 }
3272
3273 /**
3274  * Check if there is sufficient entropy in php's built-in session generation
3275  * @return bool true = there is sufficient entropy
3276  */
3277 function wfCheckEntropy() {
3278         return (
3279                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3280                         || ini_get( 'session.entropy_file' )
3281                 )
3282                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3283 }
3284
3285 /**
3286  * Override session_id before session startup if php's built-in
3287  * session generation code is not secure.
3288  */
3289 function wfFixSessionID() {
3290         // If the cookie or session id is already set we already have a session and should abort
3291         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3292                 return;
3293         }
3294
3295         // PHP's built-in session entropy is enabled if:
3296         // - entropy_file is set or you're on Windows with php 5.3.3+
3297         // - AND entropy_length is > 0
3298         // We treat it as disabled if it doesn't have an entropy length of at least 32
3299         $entropyEnabled = wfCheckEntropy();
3300
3301         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3302         if ( !$entropyEnabled ) {
3303                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3304                 session_id( MWCryptRand::generateHex( 32 ) );
3305         }
3306 }
3307
3308 /**
3309  * Initialise php session
3310  *
3311  * @param $sessionId Bool
3312  */
3313 function wfSetupSession( $sessionId = false ) {
3314         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3315                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3316         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3317                 ObjectCacheSessionHandler::install();
3318         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3319                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3320                 # hasn't already been set to the desired value (that causes errors)
3321                 ini_set( 'session.save_handler', $wgSessionHandler );
3322         }
3323         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3324         wfDebugLog( 'cookie',
3325                 'session_set_cookie_params: "' . implode( '", "',
3326                         array(
3327                                 0,
3328                                 $wgCookiePath,
3329                                 $wgCookieDomain,
3330                                 $wgCookieSecure,
3331                                 $httpOnlySafe ) ) . '"' );
3332         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3333         session_cache_limiter( 'private, must-revalidate' );
3334         if ( $sessionId ) {
3335                 session_id( $sessionId );
3336         } else {
3337                 wfFixSessionID();
3338         }
3339         wfSuppressWarnings();
3340         session_start();
3341         wfRestoreWarnings();
3342 }
3343
3344 /**
3345  * Get an object from the precompiled serialized directory
3346  *
3347  * @param $name String
3348  * @return Mixed: the variable on success, false on failure
3349  */
3350 function wfGetPrecompiledData( $name ) {
3351         global $IP;
3352
3353         $file = "$IP/serialized/$name";
3354         if ( file_exists( $file ) ) {
3355                 $blob = file_get_contents( $file );
3356                 if ( $blob ) {
3357                         return unserialize( $blob );
3358                 }
3359         }
3360         return false;
3361 }
3362
3363 /**
3364  * Get a cache key
3365  *
3366  * @param varargs
3367  * @return String
3368  */
3369 function wfMemcKey( /*... */ ) {
3370         global $wgCachePrefix;
3371         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3372         $args = func_get_args();
3373         $key = $prefix . ':' . implode( ':', $args );
3374         $key = str_replace( ' ', '_', $key );
3375         return $key;
3376 }
3377
3378 /**
3379  * Get a cache key for a foreign DB
3380  *
3381  * @param $db String
3382  * @param $prefix String
3383  * @param varargs String
3384  * @return String
3385  */
3386 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3387         $args = array_slice( func_get_args(), 2 );
3388         if ( $prefix ) {
3389                 $key = "$db-$prefix:" . implode( ':', $args );
3390         } else {
3391                 $key = $db . ':' . implode( ':', $args );
3392         }
3393         return $key;
3394 }
3395
3396 /**
3397  * Get an ASCII string identifying this wiki
3398  * This is used as a prefix in memcached keys
3399  *
3400  * @return String
3401  */
3402 function wfWikiID() {
3403         global $wgDBprefix, $wgDBname;
3404         if ( $wgDBprefix ) {
3405                 return "$wgDBname-$wgDBprefix";
3406         } else {
3407                 return $wgDBname;
3408         }
3409 }
3410
3411 /**
3412  * Split a wiki ID into DB name and table prefix
3413  *
3414  * @param $wiki String
3415  *
3416  * @return array
3417  */
3418 function wfSplitWikiID( $wiki ) {
3419         $bits = explode( '-', $wiki, 2 );
3420         if ( count( $bits ) < 2 ) {
3421                 $bits[] = '';
3422         }
3423         return $bits;
3424 }
3425
3426 /**
3427  * Get a Database object.
3428  *
3429  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3430  *            master (for write queries), DB_SLAVE for potentially lagged read
3431  *            queries, or an integer >= 0 for a particular server.
3432  *
3433  * @param $groups Mixed: query groups. An array of group names that this query
3434  *                belongs to. May contain a single string if the query is only
3435  *                in one group.
3436  *
3437  * @param string $wiki the wiki ID, or false for the current wiki
3438  *
3439  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3440  * will always return the same object, unless the underlying connection or load
3441  * balancer is manually destroyed.
3442  *
3443  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3444  * updater to ensure that a proper database is being updated.
3445  *
3446  * @return DatabaseBase
3447  */
3448 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3449         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3450 }
3451
3452 /**
3453  * Get a load balancer object.
3454  *
3455  * @param string $wiki wiki ID, or false for the current wiki
3456  * @return LoadBalancer
3457  */
3458 function wfGetLB( $wiki = false ) {
3459         return wfGetLBFactory()->getMainLB( $wiki );
3460 }
3461
3462 /**
3463  * Get the load balancer factory object
3464  *
3465  * @return LBFactory
3466  */
3467 function &wfGetLBFactory() {
3468         return LBFactory::singleton();
3469 }
3470
3471 /**
3472  * Find a file.
3473  * Shortcut for RepoGroup::singleton()->findFile()
3474  *
3475  * @param string $title or Title object
3476  * @param array $options Associative array of options:
3477  *     time:           requested time for an archived image, or false for the
3478  *                     current version. An image object will be returned which was
3479  *                     created at the specified time.
3480  *
3481  *     ignoreRedirect: If true, do not follow file redirects
3482  *
3483  *     private:        If true, return restricted (deleted) files if the current
3484  *                     user is allowed to view them. Otherwise, such files will not
3485  *                     be found.
3486  *
3487  *     bypassCache:    If true, do not use the process-local cache of File objects
3488  *
3489  * @return File, or false if the file does not exist
3490  */
3491 function wfFindFile( $title, $options = array() ) {
3492         return RepoGroup::singleton()->findFile( $title, $options );
3493 }
3494
3495 /**
3496  * Get an object referring to a locally registered file.
3497  * Returns a valid placeholder object if the file does not exist.
3498  *
3499  * @param $title Title|String
3500  * @return LocalFile|null A File, or null if passed an invalid Title
3501  */
3502 function wfLocalFile( $title ) {
3503         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3504 }
3505
3506 /**
3507  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3508  * @deprecated since 1.19
3509  */
3510 function wfStreamFile( $fname, $headers = array() ) {
3511         wfDeprecated( __FUNCTION__, '1.19' );
3512         StreamFile::stream( $fname, $headers );
3513 }
3514
3515 /**
3516  * Should low-performance queries be disabled?
3517  *
3518  * @return Boolean
3519  * @codeCoverageIgnore
3520  */
3521 function wfQueriesMustScale() {
3522         global $wgMiserMode;
3523         return $wgMiserMode
3524                 || ( SiteStats::pages() > 100000
3525                 && SiteStats::edits() > 1000000
3526                 && SiteStats::users() > 10000 );
3527 }
3528
3529 /**
3530  * Get the path to a specified script file, respecting file
3531  * extensions; this is a wrapper around $wgScriptExtension etc.
3532  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3533  *
3534  * @param string $script script filename, sans extension
3535  * @return String
3536  */
3537 function wfScript( $script = 'index' ) {
3538         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3539         if ( $script === 'index' ) {
3540                 return $wgScript;
3541         } elseif ( $script === 'load' ) {
3542                 return $wgLoadScript;
3543         } else {
3544                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3545         }
3546 }
3547
3548 /**
3549  * Get the script URL.
3550  *
3551  * @return string script URL
3552  */
3553 function wfGetScriptUrl() {
3554         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3555                 #
3556                 # as it was called, minus the query string.
3557                 #
3558                 # Some sites use Apache rewrite rules to handle subdomains,
3559                 # and have PHP set up in a weird way that causes PHP_SELF
3560                 # to contain the rewritten URL instead of the one that the
3561                 # outside world sees.
3562                 #
3563                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3564                 # provides containing the "before" URL.
3565                 return $_SERVER['SCRIPT_NAME'];
3566         } else {
3567                 return $_SERVER['URL'];
3568         }
3569 }
3570
3571 /**
3572  * Convenience function converts boolean values into "true"
3573  * or "false" (string) values
3574  *
3575  * @param $value Boolean
3576  * @return String
3577  */
3578 function wfBoolToStr( $value ) {
3579         return $value ? 'true' : 'false';
3580 }
3581
3582 /**
3583  * Get a platform-independent path to the null file, e.g. /dev/null
3584  *
3585  * @return string
3586  */
3587 function wfGetNull() {
3588         return wfIsWindows()
3589                 ? 'NUL'
3590                 : '/dev/null';
3591 }
3592
3593 /**
3594  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3595  * and waiting for it to go down, this waits for the slaves to catch up to the
3596  * master position. Use this when updating very large numbers of rows, as
3597  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3598  * a no-op if there are no slaves.
3599  *
3600  * @param $maxLag Integer (deprecated)
3601  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3602  * @param $cluster string cluster name accepted by LBFactory
3603  */
3604 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3605         $lb = ( $cluster !== false )
3606                 ? wfGetLBFactory()->getExternalLB( $cluster )
3607                 : wfGetLB( $wiki );
3608         // bug 27975 - Don't try to wait for slaves if there are none
3609         // Prevents permission error when getting master position
3610         if ( $lb->getServerCount() > 1 ) {
3611                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3612                 $pos = $dbw->getMasterPos();
3613                 // The DBMS may not support getMasterPos() or the whole
3614                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3615                 if ( $pos !== false ) {
3616                         $lb->waitForAll( $pos );
3617                 }
3618         }
3619 }
3620
3621 /**
3622  * Used to be used for outputting text in the installer/updater
3623  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3624  */
3625 function wfOut( $s ) {
3626         wfDeprecated( __FUNCTION__, '1.18' );
3627         global $wgCommandLineMode;
3628         if ( $wgCommandLineMode ) {
3629                 echo $s;
3630         } else {
3631                 echo htmlspecialchars( $s );
3632         }
3633         flush();
3634 }
3635
3636 /**
3637  * Count down from $n to zero on the terminal, with a one-second pause
3638  * between showing each number. For use in command-line scripts.
3639  * @codeCoverageIgnore
3640  * @param $n int
3641  */
3642 function wfCountDown( $n ) {
3643         for ( $i = $n; $i >= 0; $i-- ) {
3644                 if ( $i != $n ) {
3645                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3646                 }
3647                 echo $i;
3648                 flush();
3649                 if ( $i ) {
3650                         sleep( 1 );
3651                 }
3652         }
3653         echo "\n";
3654 }
3655
3656 /**
3657  * Generate a random 32-character hexadecimal token.
3658  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3659  *              characters before hashing.
3660  * @return string
3661  * @codeCoverageIgnore
3662  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3663  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3664  */
3665 function wfGenerateToken( $salt = '' ) {
3666         wfDeprecated( __METHOD__, '1.20' );
3667         $salt = serialize( $salt );
3668         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3669 }
3670
3671 /**
3672  * Replace all invalid characters with -
3673  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3674  * By default, $wgIllegalFileChars = ':'
3675  *
3676  * @param $name Mixed: filename to process
3677  * @return String
3678  */
3679 function wfStripIllegalFilenameChars( $name ) {
3680         global $wgIllegalFileChars;
3681         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3682         $name = wfBaseName( $name );
3683         $name = preg_replace(
3684                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3685                 '-',
3686                 $name
3687         );
3688         return $name;
3689 }
3690
3691 /**
3692  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3693  *
3694  * @return Integer value memory was set to.
3695  */
3696 function wfMemoryLimit() {
3697         global $wgMemoryLimit;
3698         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3699         if ( $memlimit != -1 ) {
3700                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3701                 if ( $conflimit == -1 ) {
3702                         wfDebug( "Removing PHP's memory limit\n" );
3703                         wfSuppressWarnings();
3704                         ini_set( 'memory_limit', $conflimit );
3705                         wfRestoreWarnings();
3706                         return $conflimit;
3707                 } elseif ( $conflimit > $memlimit ) {
3708                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3709                         wfSuppressWarnings();
3710                         ini_set( 'memory_limit', $conflimit );
3711                         wfRestoreWarnings();
3712                         return $conflimit;
3713                 }
3714         }
3715         return $memlimit;
3716 }
3717
3718 /**
3719  * Converts shorthand byte notation to integer form
3720  *
3721  * @param $string String
3722  * @return Integer
3723  */
3724 function wfShorthandToInteger( $string = '' ) {
3725         $string = trim( $string );
3726         if ( $string === '' ) {
3727                 return -1;
3728         }
3729         $last = $string[strlen( $string ) - 1];
3730         $val = intval( $string );
3731         switch ( $last ) {
3732                 case 'g':
3733                 case 'G':
3734                         $val *= 1024;
3735                         // break intentionally missing
3736                 case 'm':
3737                 case 'M':
3738                         $val *= 1024;
3739                         // break intentionally missing
3740                 case 'k':
3741                 case 'K':
3742                         $val *= 1024;
3743         }
3744
3745         return $val;
3746 }
3747
3748 /**
3749  * Get the normalised IETF language tag
3750  * See unit test for examples.
3751  *
3752  * @param string $code The language code.
3753  * @return String: The language code which complying with BCP 47 standards.
3754  */
3755 function wfBCP47( $code ) {
3756         $codeSegment = explode( '-', $code );
3757         $codeBCP = array();
3758         foreach ( $codeSegment as $segNo => $seg ) {
3759                 // when previous segment is x, it is a private segment and should be lc
3760                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3761                         $codeBCP[$segNo] = strtolower( $seg );
3762                 // ISO 3166 country code
3763                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3764                         $codeBCP[$segNo] = strtoupper( $seg );
3765                 // ISO 15924 script code
3766                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3767                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3768                 // Use lowercase for other cases
3769                 } else {
3770                         $codeBCP[$segNo] = strtolower( $seg );
3771                 }
3772         }
3773         $langCode = implode( '-', $codeBCP );
3774         return $langCode;
3775 }
3776
3777 /**
3778  * Get a cache object.
3779  *
3780  * @param $inputType integer Cache type, one the the CACHE_* constants.
3781  * @return BagOStuff
3782  */
3783 function wfGetCache( $inputType ) {
3784         return ObjectCache::getInstance( $inputType );
3785 }
3786
3787 /**
3788  * Get the main cache object
3789  *
3790  * @return BagOStuff
3791  */
3792 function wfGetMainCache() {
3793         global $wgMainCacheType;
3794         return ObjectCache::getInstance( $wgMainCacheType );
3795 }
3796
3797 /**
3798  * Get the cache object used by the message cache
3799  *
3800  * @return BagOStuff
3801  */
3802 function wfGetMessageCacheStorage() {
3803         global $wgMessageCacheType;
3804         return ObjectCache::getInstance( $wgMessageCacheType );
3805 }
3806
3807 /**
3808  * Get the cache object used by the parser cache
3809  *
3810  * @return BagOStuff
3811  */
3812 function wfGetParserCacheStorage() {
3813         global $wgParserCacheType;
3814         return ObjectCache::getInstance( $wgParserCacheType );
3815 }
3816
3817 /**
3818  * Get the cache object used by the language converter
3819  *
3820  * @return BagOStuff
3821  */
3822 function wfGetLangConverterCacheStorage() {
3823         global $wgLanguageConverterCacheType;
3824         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3825 }
3826
3827 /**
3828  * Call hook functions defined in $wgHooks
3829  *
3830  * @param string $event event name
3831  * @param array $args parameters passed to hook functions
3832  * @return Boolean True if no handler aborted the hook
3833  */
3834 function wfRunHooks( $event, array $args = array() ) {
3835         return Hooks::run( $event, $args );
3836 }
3837
3838 /**
3839  * Wrapper around php's unpack.
3840  *
3841  * @param string $format The format string (See php's docs)
3842  * @param $data: A binary string of binary data
3843  * @param $length integer or false: The minimum length of $data. This is to
3844  *      prevent reading beyond the end of $data. false to disable the check.
3845  *
3846  * Also be careful when using this function to read unsigned 32 bit integer
3847  * because php might make it negative.
3848  *
3849  * @throws MWException if $data not long enough, or if unpack fails
3850  * @return array Associative array of the extracted data
3851  */
3852 function wfUnpack( $format, $data, $length = false ) {
3853         if ( $length !== false ) {
3854                 $realLen = strlen( $data );
3855                 if ( $realLen < $length ) {
3856                         throw new MWException( "Tried to use wfUnpack on a "
3857                                 . "string of length $realLen, but needed one "
3858                                 . "of at least length $length."
3859                         );
3860                 }
3861         }
3862
3863         wfSuppressWarnings();
3864         $result = unpack( $format, $data );
3865         wfRestoreWarnings();
3866
3867         if ( $result === false ) {
3868                 // If it cannot extract the packed data.
3869                 throw new MWException( "unpack could not unpack binary data" );
3870         }
3871         return $result;
3872 }
3873
3874 /**
3875  * Determine if an image exists on the 'bad image list'.
3876  *
3877  * The format of MediaWiki:Bad_image_list is as follows:
3878  *    * Only list items (lines starting with "*") are considered
3879  *    * The first link on a line must be a link to a bad image
3880  *    * Any subsequent links on the same line are considered to be exceptions,
3881  *      i.e. articles where the image may occur inline.
3882  *
3883  * @param string $name the image name to check
3884  * @param $contextTitle Title|bool the page on which the image occurs, if known
3885  * @param string $blacklist wikitext of a file blacklist
3886  * @return bool
3887  */
3888 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3889         static $badImageCache = null; // based on bad_image_list msg
3890         wfProfileIn( __METHOD__ );
3891
3892         # Handle redirects
3893         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3894         if ( $redirectTitle ) {
3895                 $name = $redirectTitle->getDBkey();
3896         }
3897
3898         # Run the extension hook
3899         $bad = false;
3900         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3901                 wfProfileOut( __METHOD__ );
3902                 return $bad;
3903         }
3904
3905         $cacheable = ( $blacklist === null );
3906         if ( $cacheable && $badImageCache !== null ) {
3907                 $badImages = $badImageCache;
3908         } else { // cache miss
3909                 if ( $blacklist === null ) {
3910                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3911                 }
3912                 # Build the list now
3913                 $badImages = array();
3914                 $lines = explode( "\n", $blacklist );
3915                 foreach ( $lines as $line ) {
3916                         # List items only
3917                         if ( substr( $line, 0, 1 ) !== '*' ) {
3918                                 continue;
3919                         }
3920
3921                         # Find all links
3922                         $m = array();
3923                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3924                                 continue;
3925                         }
3926
3927                         $exceptions = array();
3928                         $imageDBkey = false;
3929                         foreach ( $m[1] as $i => $titleText ) {
3930                                 $title = Title::newFromText( $titleText );
3931                                 if ( !is_null( $title ) ) {
3932                                         if ( $i == 0 ) {
3933                                                 $imageDBkey = $title->getDBkey();
3934                                         } else {
3935                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3936                                         }
3937                                 }
3938                         }
3939
3940                         if ( $imageDBkey !== false ) {
3941                                 $badImages[$imageDBkey] = $exceptions;
3942                         }
3943                 }
3944                 if ( $cacheable ) {
3945                         $badImageCache = $badImages;
3946                 }
3947         }
3948
3949         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3950         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3951         wfProfileOut( __METHOD__ );
3952         return $bad;
3953 }