Merge "Accept diffs formatted by UnifiedDiffFormatter"

includes/DiscussionParser.php

@@ -571,6 +571,49 @@ abstract class EchoDiscussionParser {
 		return $tsMatches[0][0];
 	}
 
+	/**
+	 * Duplicates the check from the global wfDiff function to determine
+	 * if we are using internal or external diff utilities
+	 */
+	static protected function usingInternalDiff() {
+		global $wgDiff;
+
+		wfSuppressWarnings();
+		$haveDiff = $wgDiff && file_exists( $wgDiff );
+		wfRestoreWarnings();
+
+		return !$haveDiff;
+	}
+
+	/**
+	 * Strips a single space from the 2nd character of internal diff output
+	 * For more info see bug 41689.
+	 * @param $diff string
+	 */
+	static protected function fixInternalDiff( $diff ) {
+		$result = array();
+		$seenFirstLine = false;
+		foreach ( explode( "\n", $diff ) as $line ) {
+			if ( !$seenFirstLine ) {
+				$result[] = $line;
+				$seenFirstLine = true;
+				continue;
+			}
+			$len = strlen( $line );
+			if ( $len === 0 ) {
+				$result[] = '';
+			} elseif ( $len <= 2 ) {
+				$result[] = $line[0];
+			} elseif( $line[1] !== ' ' ) {
+				throw new MWException( "Internal diff did not match expected broken format. Line: `$line`" );
+			} else {
+				$result[] = $line[0] . substr( $line, 2 );
+			}
+		}
+
+		return implode( "\n", $result );
+	}
+
 	/**
 	 * Finds differences between $oldText and $newText
 	 * and returns the result in a machine-readable format.
@@ -592,6 +635,9 @@ abstract class EchoDiscussionParser {
 		$oldText = trim( $oldText ) . "\n";
 		$newText = trim( $newText ) . "\n";
 		$diff = wfDiff( $oldText, $newText, '-u -w' );
+		if ( self::usingInternalDiff() ) {
+			$diff = self::fixInternalDiff( $diff );
+		}
 
 		$old_lines = explode( "\n", $oldText );
 		$new_lines = explode( "\n", $newText );

tests/DiscussionParserTest.php

@@ -8,6 +8,36 @@ class EchoDiscussionParserTest extends MediaWikiTestCase {
 	// - stripSignature
 	// - getNotifiedUsersForComment
 
+	public function testDiscussionParserAcceptsInternalDiff() {
+		global $wgDiff;
+
+		$origWgDiff = $wgDiff;
+		$wgDiff = '/does/not/exist/or/at/least/we/hope/not';
+		try {
+			$res = EchoDiscussionParser::getMachineReadableDiff(
+				<<<TEXT
+line 1
+line 2
+line 3
+line 4
+TEXT
+				,
+				<<<TEXT
+line 1
+line c
+line 4
+TEXT
+			);
+		} catch ( MWException $e ) {
+			$wgDiff = $origWgDiff;
+			throw $e;
+		}
+		$wgDiff = $origWgDiff;
+
+		// Test failure occurs when MWException is thrown due to parsing failure
+		$this->assertTrue( true );
+	}
+
 	public function testTimestampRegex() {
 		$exemplarTimestamp = self::getExemplarTimestamp();
 		$timestampRegex = EchoDiscussionParser::getTimestampRegex();