From 430f653e72c9f1b5d168a0f50dcc9c4286a87d05 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Fri, 18 Feb 2011 07:36:11 +0000
Subject: [PATCH] * For readability, use /x in regexes. Removed the start and
 end slashes from the input to ParseMaster::add(), to avoid confusion over the
 lack of a /x modifier in that input. * Broke up several regexes and added
 comments, so that humans might be able to understand them. * Tested
 md5(minify(jquery.js)) as before. Checked speed, it's the same.

---
 includes/libs/JavaScriptDistiller.php | 75 ++++++++++++++++++++-------
 1 file changed, 56 insertions(+), 19 deletions(-)

diff --git a/includes/libs/JavaScriptDistiller.php b/includes/libs/JavaScriptDistiller.php
index b377ac59d5..1c44e6bfa5 100644
--- a/includes/libs/JavaScriptDistiller.php
+++ b/includes/libs/JavaScriptDistiller.php
@@ -31,13 +31,13 @@ class JavaScriptDistiller {
 	public static function stripHorizontalSpace( $script ) {
 		$parser = self::createParser();
 		// Collapse horizontal whitespaces between variable names into a single space
-		$parser->add( '/(\b|\$)[ \t]+(\b|\$)/', '$2 $3' );
+		$parser->add( '(\b|\$) [ \t]+ (\b|\$)', '$2 $3' );
 		// Collapse horizontal whitespaces between unary operators into a single space
-		$parser->add( '/([+\-])[ \t]+([+\-])/', '$2 $3' );
+		$parser->add( '([+\-]) [ \t]+ ([+\-])', '$2 $3' );
 		// Remove all remaining un-protected horizontal whitespace
-		$parser->add( '/[ \t]+/');
+		$parser->add( '[ \t]+');
 		// Collapse multiple vertical whitespaces with some horizontal spaces between them
-		$parser->add( '/[\r\n]+[ \t]*[\r\n]+/', "\n" );
+		$parser->add( '[\r\n]+ [ \t]* [\r\n]+', "\n" );
 		// Execute and return
 		return $parser->exec($script);
 	}
@@ -45,16 +45,16 @@ class JavaScriptDistiller {
 	public static function stripVerticalSpace( $script ) {
 		$parser = self::createParser();
 		// Collapse whitespaces between and after a ){ pair (function definitions)
-		$parser->add( '/\)\s+\{\s+/', '){' );
+		$parser->add( '\) \s+ \{ \s+', '){' );
 		// Collapse whitespaces between and after a ({ pair (JSON argument)
-		$parser->add( '/\(\s+\{\s+/', '({' );
+		$parser->add( '\( \s+ \{ \s+', '({' );
 		// Collapse whitespaces between a parenthesis and a period (call chaining)
-		$parser->add( '/\)\s+\./', ').');
+		$parser->add( '\) \s+ \.', ').');
 		// Collapse vertical whitespaces which come directly after a semicolon or a comma
-		$parser->add( '/([;,])\s+/', '$2' );
+		$parser->add( '( [;,] ) \s+', '$2' );
 		// Collapse whitespaces between multiple parenthesis/brackets of similar direction
-		$parser->add( '/([\)\}])\s+([\)\}])/', '$2$3' );
-		$parser->add( '/([\(\{])\\s+([\(\{])/', '$2$3' );
+		$parser->add( '( [\)\}] ) \s+ ( [\)\}] )', '$2$3' );
+		$parser->add( '( [\(\{] ) \s+ ( [\(\{] )', '$2$3' );
 		return $parser->exec( $script );
 	}
 
@@ -77,15 +77,52 @@ class JavaScriptDistiller {
 		// Protect strings. The original code had [^\'\\v] here, but that didn't armor multiline
 		// strings correctly. This also armors multiline strings that don't have backslashes at the
 		// end of the line (these are invalid), but that's fine because we're just armoring here.
-		$parser->add( '/\'([^\'\\\\]*(\\\\(.|[\r\n])[^\'\\\\]*)*)\'/', '$1' );
-		$parser->add( '/"([^"\\\\]*(\\\\(.|[\r\n])[^"\\\\]*)*)"/', '$1' );
+
+		// Single quotes
+		$parser->add( 
+			'\' (' . // start quote
+			'[^\'\\\\]*' . // a run of non-special characters
+			'(' .
+				'\\\\ ( . | [\r\n] )' . // a backslash followed by a character or line ending
+				'[^\'\\\\]*' . // a run of non-special characters
+			')*' . // any number of the above
+			') \'', // end quote
+			'$1' );
+
+		// Double quotes: same as above
+		$parser->add( '" ( [^"\\\\]* ( \\\\ ( . | [\r\n] ) [^"\\\\]* )* ) "', '$1' );
+
 		// Protect regular expressions
-		$parser->add( '/[ \t]+((\/[^\r\n\*][^\/\r\n\\\\]*(\\\\.[^\/\r\n\\\\]*)*\/(i|g)*))/', '$1' );
-		$parser->add( '/([^\w\$\/\'"*)\?:](\/[^\r\n\*][^\/\r\n\\\\]*(\\\\.[^\/\r\n\\\\]*)*\/(i|g)*))/', '$1' );
-		// Remove comments
-		$parser->add( '/\/\*(.|[\r\n])*?\*\//' );
+		// Regular expression with whitespace before it
+		$parser->add(
+			'[ \t]+ ( ( \/' . // whitespace then start slash
+			'[^\r\n\*]' . // not a comment-start or line ending
+			'[^\/\r\n\\\\]*' . // a sequence of non-special characters
+			'(' . 
+				'\\\\.' . // an escaped dot
+				'[^\/\r\n\\\\]*' . // a sequence of non-special characters
+			')*' . // any number of the above
+			'\/(i|g)*' . // pattern end, optional modifier
+			') )', 
+			'$1' );
+		// Regular expression with an operator before it
+		$parser->add( 
+			'( [^\w\$\/\'"*)\?:] (\/' . // certain kinds of punctuation and then start slash
+			'[^\r\n\*]' . // not a comment-start or line ending
+			'[^\/\r\n\\\\]*' . // a sequence of non-special characters
+			'(' . 
+				'\\\\.' . // an escaped dot
+				'[^\/\r\n\\\\]*' . // a sequence of non-special characters
+			')*' . // any number of the above
+			'\/(i|g)*)' . // pattern end, optional modifier
+			')',
+			'$1' );
+
+		// C-style comment: use non-greedy repetition to find the end
+		$parser->add( '\/ \* ( . | [\r\n] )*? \* \/' );
+
 		// Preserve the newline after a C++-style comment -- bug 27046
-		$parser->add( '/\/\/[^\r\n]*([\r\n])/', '$2' );
+		$parser->add( '\/ \/ [^\r\n]* ( [\r\n] )', '$2' );
 		return $parser;
 	}
 }
@@ -160,9 +197,9 @@ class ParseMaster {
 		// simulate the _patterns.toSTring of Dean
 		$regexp = '/';
 		foreach ($this->_patterns as $reg) {
-			$regexp .= '(' . substr($reg[self::EXPRESSION], 1, -1) . ')|';
+			$regexp .= '(' . $reg[self::EXPRESSION] . ')|';
 		}
-		$regexp = substr($regexp, 0, -1) . '/S';
+		$regexp = substr($regexp, 0, -1) . '/Sx';
 		$regexp .= ($this->ignoreCase) ? 'i' : '';
 
 		$string = $this->_escape($string, $this->escapeChar);
-- 
2.20.1