Update to MediaWiki 1.24.1

1 files changed, 372 insertions, 0 deletions

diff --git a/includes/exception/MWExceptionHandler.php b/includes/exception/MWExceptionHandler.php
new file mode 100644
index 00000000..71917e13
--- /dev/null
+++ b/includes/exception/MWExceptionHandler.php
@@ -0,0 +1,372 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * Handler class for MWExceptions
+ * @ingroup Exception
+ */
+class MWExceptionHandler {
+	/**
+	 * Install an exception handler for MediaWiki exception types.
+	 */
+	public static function installHandler() {
+		set_exception_handler( array( 'MWExceptionHandler', 'handle' ) );
+	}
+
+	/**
+	 * Report an exception to the user
+	 * @param Exception $e
+	 */
+	protected static function report( Exception $e ) {
+		global $wgShowExceptionDetails;
+
+		$cmdLine = MWException::isCommandLine();
+
+		if ( $e instanceof MWException ) {
+			try {
+				// Try and show the exception prettily, with the normal skin infrastructure
+				$e->report();
+			} catch ( Exception $e2 ) {
+				// Exception occurred from within exception handler
+				// Show a simpler error message for the original exception,
+				// don't try to invoke report()
+				$message = "MediaWiki internal error.\n\n";
+
+				if ( $wgShowExceptionDetails ) {
+					$message .= 'Original exception: ' . self::getLogMessage( $e ) .
+						"\nBacktrace:\n" . self::getRedactedTraceAsString( $e ) .
+						"\n\nException caught inside exception handler: " . self::getLogMessage( $e2 ) .
+						"\nBacktrace:\n" . self::getRedactedTraceAsString( $e2 );
+				} else {
+					$message .= "Exception caught inside exception handler.\n\n" .
+						"Set \$wgShowExceptionDetails = true; at the bottom of LocalSettings.php " .
+						"to show detailed debugging information.";
+				}
+
+				$message .= "\n";
+
+				if ( $cmdLine ) {
+					self::printError( $message );
+				} else {
+					echo nl2br( htmlspecialchars( $message ) ) . "\n";
+				}
+			}
+		} else {
+			$message = "Unexpected non-MediaWiki exception encountered, of type \"" .
+				get_class( $e ) . "\"";
+
+			if ( $wgShowExceptionDetails ) {
+				$message .= "\n" . MWExceptionHandler::getLogMessage( $e ) . "\nBacktrace:\n" .
+					self::getRedactedTraceAsString( $e ) . "\n";
+			}
+
+			if ( $cmdLine ) {
+				self::printError( $message );
+			} else {
+				echo nl2br( htmlspecialchars( $message ) ) . "\n";
+			}
+		}
+	}
+
+	/**
+	 * Print a message, if possible to STDERR.
+	 * Use this in command line mode only (see isCommandLine)
+	 *
+	 * @param string $message Failure text
+	 */
+	public static function printError( $message ) {
+		# NOTE: STDERR may not be available, especially if php-cgi is used from the
+		# command line (bug #15602). Try to produce meaningful output anyway. Using
+		# echo may corrupt output to STDOUT though.
+		if ( defined( 'STDERR' ) ) {
+			fwrite( STDERR, $message );
+		} else {
+			echo $message;
+		}
+	}
+
+	/**
+	 * If there are any open database transactions, roll them back and log
+	 * the stack trace of the exception that should have been caught so the
+	 * transaction could be aborted properly.
+	 * @since 1.23
+	 * @param Exception $e
+	 */
+	public static function rollbackMasterChangesAndLog( Exception $e ) {
+		$factory = wfGetLBFactory();
+		if ( $factory->hasMasterChanges() ) {
+			wfDebugLog( 'Bug56269',
+				'Exception thrown with an uncommited database transaction: ' .
+					MWExceptionHandler::getLogMessage( $e ) . "\n" .
+					$e->getTraceAsString()
+			);
+			$factory->rollbackMasterChanges();
+		}
+	}
+
+	/**
+	 * Exception handler which simulates the appropriate catch() handling:
+	 *
+	 *   try {
+	 *       ...
+	 *   } catch ( MWException $e ) {
+	 *       $e->report();
+	 *   } catch ( Exception $e ) {
+	 *       echo $e->__toString();
+	 *   }
+	 * @param Exception $e
+	 */
+	public static function handle( $e ) {
+		global $wgFullyInitialised;
+
+		self::rollbackMasterChangesAndLog( $e );
+
+		self::report( $e );
+
+		// Final cleanup
+		if ( $wgFullyInitialised ) {
+			try {
+				// uses $wgRequest, hence the $wgFullyInitialised condition
+				wfLogProfilingData();
+			} catch ( Exception $e ) {
+			}
+		}
+
+		// Exit value should be nonzero for the benefit of shell jobs
+		exit( 1 );
+	}
+
+	/**
+	 * Generate a string representation of an exception's stack trace
+	 *
+	 * Like Exception::getTraceAsString, but replaces argument values with
+	 * argument type or class name.
+	 *
+	 * @param Exception $e
+	 * @return string
+	 */
+	public static function getRedactedTraceAsString( Exception $e ) {
+		$text = '';
+
+		foreach ( self::getRedactedTrace( $e ) as $level => $frame ) {
+			if ( isset( $frame['file'] ) && isset( $frame['line'] ) ) {
+				$text .= "#{$level} {$frame['file']}({$frame['line']}): ";
+			} else {
+				// 'file' and 'line' are unset for calls via call_user_func (bug 55634)
+				// This matches behaviour of Exception::getTraceAsString to instead
+				// display "[internal function]".
+				$text .= "#{$level} [internal function]: ";
+			}
+
+			if ( isset( $frame['class'] ) ) {
+				$text .= $frame['class'] . $frame['type'] . $frame['function'];
+			} else {
+				$text .= $frame['function'];
+			}
+
+			if ( isset( $frame['args'] ) ) {
+				$text .= '(' . implode( ', ', $frame['args'] ) . ")\n";
+			} else {
+				$text .= "()\n";
+			}
+		}
+
+		$level = $level + 1;
+		$text .= "#{$level} {main}";
+
+		return $text;
+	}
+
+	/**
+	 * Return a copy of an exception's backtrace as an array.
+	 *
+	 * Like Exception::getTrace, but replaces each element in each frame's
+	 * argument array with the name of its class (if the element is an object)
+	 * or its type (if the element is a PHP primitive).
+	 *
+	 * @since 1.22
+	 * @param Exception $e
+	 * @return array
+	 */
+	public static function getRedactedTrace( Exception $e ) {
+		return array_map( function ( $frame ) {
+			if ( isset( $frame['args'] ) ) {
+				$frame['args'] = array_map( function ( $arg ) {
+					return is_object( $arg ) ? get_class( $arg ) : gettype( $arg );
+				}, $frame['args'] );
+			}
+			return $frame;
+		}, $e->getTrace() );
+	}
+
+	/**
+	 * Get the ID for this error.
+	 *
+	 * The ID is saved so that one can match the one output to the user (when
+	 * $wgShowExceptionDetails is set to false), to the entry in the debug log.
+	 *
+	 * @since 1.22
+	 * @param Exception $e
+	 * @return string
+	 */
+	public static function getLogId( Exception $e ) {
+		if ( !isset( $e->_mwLogId ) ) {
+			$e->_mwLogId = wfRandomString( 8 );
+		}
+		return $e->_mwLogId;
+	}
+
+	/**
+	 * If the exception occurred in the course of responding to a request,
+	 * returns the requested URL. Otherwise, returns false.
+	 *
+	 * @since 1.23
+	 * @return string|bool
+	 */
+	public static function getURL() {
+		global $wgRequest;
+		if ( !isset( $wgRequest ) || $wgRequest instanceof FauxRequest ) {
+			return false;
+		}
+		return $wgRequest->getRequestURL();
+	}
+
+	/**
+	 * Return the requested URL and point to file and line number from which the
+	 * exception occurred.
+	 *
+	 * @since 1.22
+	 * @param Exception $e
+	 * @return string
+	 */
+	public static function getLogMessage( Exception $e ) {
+		$id = self::getLogId( $e );
+		$file = $e->getFile();
+		$line = $e->getLine();
+		$message = $e->getMessage();
+		$url = self::getURL() ?: '[no req]';
+
+		return "[$id] $url   Exception from line $line of $file: $message";
+	}
+
+	/**
+	 * Serialize an Exception object to JSON.
+	 *
+	 * The JSON object will have keys 'id', 'file', 'line', 'message', and
+	 * 'url'. These keys map to string values, with the exception of 'line',
+	 * which is a number, and 'url', which may be either a string URL or or
+	 * null if the exception did not occur in the context of serving a web
+	 * request.
+	 *
+	 * If $wgLogExceptionBacktrace is true, it will also have a 'backtrace'
+	 * key, mapped to the array return value of Exception::getTrace, but with
+	 * each element in each frame's "args" array (if set) replaced with the
+	 * argument's class name (if the argument is an object) or type name (if
+	 * the argument is a PHP primitive).
+	 *
+	 * @par Sample JSON record ($wgLogExceptionBacktrace = false):
+	 * @code
+	 *  {
+	 *    "id": "c41fb419",
+	 *    "file": "/var/www/mediawiki/includes/cache/MessageCache.php",
+	 *    "line": 704,
+	 *    "message": "Non-string key given",
+	 *    "url": "/wiki/Main_Page"
+	 *  }
+	 * @endcode
+	 *
+	 * @par Sample JSON record ($wgLogExceptionBacktrace = true):
+	 * @code
+	 *  {
+	 *    "id": "dc457938",
+	 *    "file": "/vagrant/mediawiki/includes/cache/MessageCache.php",
+	 *    "line": 704,
+	 *    "message": "Non-string key given",
+	 *    "url": "/wiki/Main_Page",
+	 *    "backtrace": [{
+	 *      "file": "/vagrant/mediawiki/extensions/VisualEditor/VisualEditor.hooks.php",
+	 *      "line": 80,
+	 *      "function": "get",
+	 *      "class": "MessageCache",
+	 *      "type": "->",
+	 *      "args": ["array"]
+	 *    }]
+	 *  }
+	 * @endcode
+	 *
+	 * @since 1.23
+	 * @param Exception $e
+	 * @param bool $pretty Add non-significant whitespace to improve readability (default: false).
+	 * @param int $escaping Bitfield consisting of FormatJson::.*_OK class constants.
+	 * @return string|bool JSON string if successful; false upon failure
+	 */
+	public static function jsonSerializeException( Exception $e, $pretty = false, $escaping = 0 ) {
+		global $wgLogExceptionBacktrace;
+
+		$exceptionData = array(
+			'id' => self::getLogId( $e ),
+			'file' => $e->getFile(),
+			'line' => $e->getLine(),
+			'message' => $e->getMessage(),
+		);
+
+		// Because MediaWiki is first and foremost a web application, we set a
+		// 'url' key unconditionally, but set it to null if the exception does
+		// not occur in the context of a web request, as a way of making that
+		// fact visible and explicit.
+		$exceptionData['url'] = self::getURL() ?: null;
+
+		if ( $wgLogExceptionBacktrace ) {
+			// Argument values may not be serializable, so redact them.
+			$exceptionData['backtrace'] = self::getRedactedTrace( $e );
+		}
+
+		return FormatJson::encode( $exceptionData, $pretty, $escaping );
+	}
+
+	/**
+	 * Log an exception to the exception log (if enabled).
+	 *
+	 * This method must not assume the exception is an MWException,
+	 * it is also used to handle PHP errors or errors from other libraries.
+	 *
+	 * @since 1.22
+	 * @param Exception $e
+	 */
+	public static function logException( Exception $e ) {
+		global $wgLogExceptionBacktrace;
+
+		if ( !( $e instanceof MWException ) || $e->isLoggable() ) {
+			$log = self::getLogMessage( $e );
+			if ( $wgLogExceptionBacktrace ) {
+				wfDebugLog( 'exception', $log . "\n" . $e->getTraceAsString() );
+			} else {
+				wfDebugLog( 'exception', $log );
+			}
+
+			$json = self::jsonSerializeException( $e, false, FormatJson::ALL_OK );
+			if ( $json !== false ) {
+				wfDebugLog( 'exception-json', $json, 'private' );
+			}
+		}
+
+	}
+
+}