Merge "Fix some omitted colons in Spanish magic word l10n"
[lhc/web/wiklou.git] / includes / libs / CSSMin.php
index 4f142fc..e3a3e2c 100644 (file)
@@ -38,7 +38,8 @@ class CSSMin {
         * which when base64 encoded will result in a 1/3 increase in size.
         */
        const EMBED_SIZE_LIMIT = 24576;
-       const URL_REGEX = 'url\(\s*[\'"]?(?P<file>[^\?\)\'"]*)(?P<query>\??[^\)\'"]*)[\'"]?\s*\)';
+       const URL_REGEX = 'url\(\s*[\'"]?(?P<file>[^\?\)\'"]*?)(?P<query>\?[^\)\'"]*?|)[\'"]?\s*\)';
+       const EMBED_REGEX = '\/\*\s*\@embed\s*\*\/';
 
        /* Protected Static Members */
 
@@ -52,6 +53,7 @@ class CSSMin {
                'tif' => 'image/tiff',
                'tiff' => 'image/tiff',
                'xbm' => 'image/x-xbitmap',
+               'svg' => 'image/svg+xml',
        );
 
        /* Static Methods */
@@ -59,23 +61,38 @@ class CSSMin {
        /**
         * Gets a list of local file paths which are referenced in a CSS style sheet
         *
+        * This function will always return an empty array if the second parameter is not given or null
+        * for backwards-compatibility.
+        *
         * @param string $source CSS data to remap
         * @param string $path File path where the source was read from (optional)
         * @return array List of local file references
         */
        public static function getLocalFileReferences( $source, $path = null ) {
+               if ( $path === null ) {
+                       return array();
+               }
+
+               $path = rtrim( $path, '/' ) . '/';
                $files = array();
+
                $rFlags = PREG_OFFSET_CAPTURE | PREG_SET_ORDER;
                if ( preg_match_all( '/' . self::URL_REGEX . '/', $source, $matches, $rFlags ) ) {
                        foreach ( $matches as $match ) {
-                               $file = ( isset( $path )
-                                       ? rtrim( $path, '/' ) . '/'
-                                       : '' ) . "{$match['file'][0]}";
+                               $url = $match['file'][0];
 
-                               // Only proceed if we can access the file
-                               if ( !is_null( $path ) && file_exists( $file ) ) {
-                                       $files[] = $file;
+                               // Skip fully-qualified and protocol-relative URLs and data URIs
+                               if ( substr( $url, 0, 2 ) === '//' || parse_url( $url, PHP_URL_SCHEME ) ) {
+                                       break;
                                }
+
+                               $file = $path . $url;
+                               // Skip non-existent files
+                               if ( file_exists( $file ) ) {
+                                       break;
+                               }
+
+                               $files[] = $file;
                        }
                }
                return $files;
@@ -140,8 +157,26 @@ class CSSMin {
        }
 
        /**
-        * Remaps CSS URL paths and automatically embeds data URIs for URL rules
-        * preceded by an /* @embed * / comment
+        * Build a CSS 'url()' value for the given URL, quoting parentheses (and other funny characters)
+        * and escaping quotes as necessary.
+        *
+        * @param string $url URL to process
+        * @return string 'url()' value, usually just `"url($url)"`, quoted/escaped if necessary
+        */
+       public static function buildUrlValue( $url ) {
+               // The list below has been crafted to match URLs such as:
+               //   scheme://user@domain:port/~user/fi%20le.png?query=yes&really=y+s
+               //   data:image/png;base64,R0lGODlh/+==
+               if ( preg_match( '!^[\w\d:@/~.%+;,?&=-]+$!', $url ) ) {
+                       return "url($url)";
+               } else {
+                       return 'url("' . strtr( $url, array( '\\' => '\\\\', '"' => '\\"' ) ) . '")';
+               }
+       }
+
+       /**
+        * Remaps CSS URL paths and automatically embeds data URIs for CSS rules or url() values
+        * preceded by an / * @embed * / comment.
         *
         * @param string $source CSS data to remap
         * @param string $local File path where the source was read from
@@ -150,89 +185,116 @@ class CSSMin {
         * @return string Remapped CSS data
         */
        public static function remap( $source, $local, $remote, $embedData = true ) {
-               $pattern = '/((?P<embed>\s*\/\*\s*\@embed\s*\*\/)(?P<pre>[^\;\}]*))?' .
-                       self::URL_REGEX . '(?P<post>[^;]*)[\;]?/';
-               $offset = 0;
-               while ( preg_match( $pattern, $source, $match, PREG_OFFSET_CAPTURE, $offset ) ) {
-                       // Skip fully-qualified URLs and data URIs
-                       $urlScheme = parse_url( $match['file'][0], PHP_URL_SCHEME );
-                       if ( $urlScheme ) {
-                               // Move the offset to the end of the match, leaving it alone
-                               $offset = $match[0][1] + strlen( $match[0][0] );
-                               continue;
-                       }
-                       // URLs with absolute paths like /w/index.php need to be expanded
-                       // to absolute URLs but otherwise left alone
-                       if ( $match['file'][0] !== '' && $match['file'][0][0] === '/' ) {
-                               // Replace the file path with an expanded (possibly protocol-relative) URL
-                               // ...but only if wfExpandUrl() is even available.
-                               // This will not be the case if we're running outside of MW
-                               $lengthIncrease = 0;
-                               if ( function_exists( 'wfExpandUrl' ) ) {
-                                       $expanded = wfExpandUrl( $match['file'][0], PROTO_RELATIVE );
-                                       $origLength = strlen( $match['file'][0] );
-                                       $lengthIncrease = strlen( $expanded ) - $origLength;
-                                       $source = substr_replace( $source, $expanded,
-                                               $match['file'][1], $origLength
-                                       );
-                               }
-                               // Move the offset to the end of the match, leaving it alone
-                               $offset = $match[0][1] + strlen( $match[0][0] ) + $lengthIncrease;
-                               continue;
+               // High-level overview:
+               // * For each CSS rule in $source that includes at least one url() value:
+               //   * Check for an @embed comment at the start indicating that all URIs should be embedded
+               //   * For each url() value:
+               //     * Check for an @embed comment directly preceding the value
+               //     * If either @embed comment exists:
+               //       * Embedding the URL as data: URI, if it's possible / allowed
+               //       * Otherwise remap the URL to work in generated stylesheets
+
+               // Guard against trailing slashes, because "some/remote/../foo.png"
+               // resolves to "some/remote/foo.png" on (some?) clients (bug 27052).
+               if ( substr( $remote, -1 ) == '/' ) {
+                       $remote = substr( $remote, 0, -1 );
+               }
+
+               // Note: This will not correctly handle cases where ';', '{' or '}' appears in the rule itself,
+               // e.g. in a quoted string. You are advised not to use such characters in file names.
+               // We also match start/end of the string to be consistent in edge-cases ('@import url(…)').
+               $pattern = '/(?:^|[;{])\K[^;{}]*' . CSSMin::URL_REGEX . '[^;}]*(?=[;}]|$)/';
+               return preg_replace_callback( $pattern, function ( $matchOuter ) use ( $local, $remote, $embedData ) {
+                       $rule = $matchOuter[0];
+
+                       // Check for global @embed comment and remove it
+                       $embedAll = false;
+                       $rule = preg_replace( '/^(\s*)' . CSSMin::EMBED_REGEX . '\s*/', '$1', $rule, 1, $embedAll );
+
+                       // Build two versions of current rule: with remapped URLs and with embedded data: URIs (where possible)
+                       $pattern = '/(?P<embed>' . CSSMin::EMBED_REGEX . '\s*|)' . CSSMin::URL_REGEX . '/';
+
+                       $ruleWithRemapped = preg_replace_callback( $pattern, function ( $match ) use ( $local, $remote ) {
+                               $remapped = CSSMin::remapOne( $match['file'], $match['query'], $local, $remote, false );
+                               return CSSMin::buildUrlValue( $remapped );
+                       }, $rule );
+
+                       if ( $embedData ) {
+                               $ruleWithEmbedded = preg_replace_callback( $pattern, function ( $match ) use ( $embedAll, $local, $remote ) {
+                                       $embed = $embedAll || $match['embed'];
+                                       $embedded = CSSMin::remapOne( $match['file'], $match['query'], $local, $remote, $embed );
+                                       return CSSMin::buildUrlValue( $embedded );
+                               }, $rule );
                        }
 
-                       // Guard against double slashes, because "some/remote/../foo.png"
-                       // resolves to "some/remote/foo.png" on (some?) clients (bug 27052).
-                       if ( substr( $remote, -1 ) == '/' ) {
-                               $remote = substr( $remote, 0, -1 );
+                       if ( $embedData && $ruleWithEmbedded !== $ruleWithRemapped ) {
+                               // Build 2 CSS properties; one which uses a base64 encoded data URI in place
+                               // of the @embed comment to try and retain line-number integrity, and the
+                               // other with a remapped an versioned URL and an Internet Explorer hack
+                               // making it ignored in all browsers that support data URIs
+                               return "$ruleWithEmbedded;$ruleWithRemapped!ie";
+                       } else {
+                               // No reason to repeat twice
+                               return $ruleWithRemapped;
                        }
+               }, $source );
+       }
+
+       /**
+        * Remap or embed a CSS URL path.
+        *
+        * @param string $file URL to remap/embed
+        * @param string $query
+        * @param string $local File path where the source was read from
+        * @param string $remote URL path to the file
+        * @param bool $embed Whether to do any data URI embedding
+        * @return string Remapped/embedded URL data
+        */
+       public static function remapOne( $file, $query, $local, $remote, $embed ) {
+               // The full URL possibly with query, as passed to the 'url()' value in CSS
+               $url = $file . $query;
 
-                       // Shortcuts
-                       $embed = $match['embed'][0];
-                       $pre = $match['pre'][0];
-                       $post = $match['post'][0];
-                       $query = $match['query'][0];
-                       $url = "{$remote}/{$match['file'][0]}";
-                       $file = "{$local}/{$match['file'][0]}";
+               // Skip fully-qualified and protocol-relative URLs and data URIs
+               if ( substr( $url, 0, 2 ) === '//' || parse_url( $url, PHP_URL_SCHEME ) ) {
+                       return $url;
+               }
 
-                       $replacement = false;
+               // URLs with absolute paths like /w/index.php need to be expanded
+               // to absolute URLs but otherwise left alone
+               if ( $url !== '' && $url[0] === '/' ) {
+                       // Replace the file path with an expanded (possibly protocol-relative) URL
+                       // ...but only if wfExpandUrl() is even available.
+                       // This will not be the case if we're running outside of MW
+                       if ( function_exists( 'wfExpandUrl' ) ) {
+                               return wfExpandUrl( $url, PROTO_RELATIVE );
+                       } else {
+                               return $url;
+                       }
+               }
 
-                       if ( $local !== false && file_exists( $file ) ) {
+               if ( $local === false ) {
+                       // Assume that all paths are relative to $remote, and make them absolute
+                       return $remote . '/' . $url;
+               } else {
+                       // We drop the query part here and instead make the path relative to $remote
+                       $url = "{$remote}/{$file}";
+                       // Path to the actual file on the filesystem
+                       $localFile = "{$local}/{$file}";
+                       if ( file_exists( $localFile ) ) {
                                // Add version parameter as a time-stamp in ISO 8601 format,
                                // using Z for the timezone, meaning GMT
-                               $url .= '?' . gmdate( 'Y-m-d\TH:i:s\Z', round( filemtime( $file ), -2 ) );
-                               // Embedding requires a bit of extra processing, so let's skip that if we can
-                               if ( $embedData && $embed && $match['embed'][1] > 0 ) {
-                                       $data = self::encodeImageAsDataURI( $file );
+                               $url .= '?' . gmdate( 'Y-m-d\TH:i:s\Z', round( filemtime( $localFile ), -2 ) );
+                               if ( $embed ) {
+                                       $data = self::encodeImageAsDataURI( $localFile );
                                        if ( $data !== false ) {
-                                               // Build 2 CSS properties; one which uses a base64 encoded data URI in place
-                                               // of the @embed comment to try and retain line-number integrity, and the
-                                               // other with a remapped an versioned URL and an Internet Explorer hack
-                                               // making it ignored in all browsers that support data URIs
-                                               $replacement = "{$pre}url({$data}){$post};{$pre}url({$url}){$post}!ie;";
+                                               return $data;
                                        }
                                }
-                               if ( $replacement === false ) {
-                                       // Assume that all paths are relative to $remote, and make them absolute
-                                       $replacement = "{$embed}{$pre}url({$url}){$post};";
-                               }
-                       } elseif ( $local === false ) {
-                               // Assume that all paths are relative to $remote, and make them absolute
-                               $replacement = "{$embed}{$pre}url({$url}{$query}){$post};";
-                       }
-                       if ( $replacement !== false ) {
-                               // Perform replacement on the source
-                               $source = substr_replace(
-                                       $source, $replacement, $match[0][1], strlen( $match[0][0] )
-                               );
-                               // Move the offset to the end of the replacement in the source
-                               $offset = $match[0][1] + strlen( $replacement );
-                               continue;
                        }
-                       // Move the offset to the end of the match, leaving it alone
-                       $offset = $match[0][1] + strlen( $match[0][0] );
+                       // If any of these conditions failed (file missing, we don't want to embed it
+                       // or it's not embeddable), return the URL (possibly with ?timestamp part)
+                       return $url;
                }
-               return $source;
        }
 
        /**