From 039e19f1c7300e48ab86c8ee4885a1c2d2224aba Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@gmail.com>
Date: Sun, 29 Mar 2015 02:14:08 -0700
Subject: [PATCH] exception: Log fatal errors to a new 'fatal' log group

'error' is currently disabled in Wikimedia production, but we still need
to log stack traces for fatals.

Bug: T89169
Change-Id: Id0255651f228037152b87022f5eb696c1050b9ec
---
 includes/exception/MWExceptionHandler.php | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/includes/exception/MWExceptionHandler.php b/includes/exception/MWExceptionHandler.php
index 5644231a18..7110361066 100644
--- a/includes/exception/MWExceptionHandler.php
+++ b/includes/exception/MWExceptionHandler.php
@@ -179,6 +179,7 @@ class MWExceptionHandler {
 	 */
 	public static function handleError( $level, $message, $file = null, $line = null ) {
 		// Map error constant to error name (reverse-engineer PHP error reporting)
+		$channel = 'error';
 		switch ( $level ) {
 			case E_ERROR:
 			case E_CORE_ERROR:
@@ -187,6 +188,7 @@ class MWExceptionHandler {
 			case E_RECOVERABLE_ERROR:
 			case E_PARSE:
 				$levelName = 'Error';
+				$channel = 'fatal';
 				break;
 			case E_WARNING:
 			case E_CORE_WARNING:
@@ -207,6 +209,7 @@ class MWExceptionHandler {
 				break;
 			case /* HHVM's FATAL_ERROR */ 16777217:
 				$levelName = 'Fatal';
+				$channel = 'fatal';
 				break;
 			default:
 				$levelName = 'Unknown error';
@@ -214,7 +217,7 @@ class MWExceptionHandler {
 		}
 
 		$e = new ErrorException( "PHP $levelName: $message", 0, $level, $file, $line );
-		self::logError( $e );
+		self::logError( $e, $channel );
 
 		// This handler is for logging only. Return false will instruct PHP
 		// to continue regular handling.
@@ -257,7 +260,7 @@ TXT;
 				// @codingStandardsIgnoreEnd
 			}
 			$e = new ErrorException( $msg, 0, $lastError['type'] );
-			self::logError( $e );
+			self::logError( $e, 'fatal' );
 		}
 	}
 
@@ -489,8 +492,9 @@ TXT;
 	 *
 	 * @since 1.25
 	 * @param ErrorException $e
+	 * @param string $channel
 	*/
-	protected static function logError( ErrorException $e ) {
+	protected static function logError( ErrorException $e, $channel ) {
 		global $wgLogExceptionBacktrace;
 
 		// The set_error_handler callback is independent from error_reporting.
@@ -498,16 +502,16 @@ TXT;
 		if ( ( error_reporting() & $e->getSeverity() ) !== 0 ) {
 			$log = self::getLogMessage( $e );
 			if ( $wgLogExceptionBacktrace ) {
-				wfDebugLog( 'error', $log . "\n" . $e->getTraceAsString() );
+				wfDebugLog( $channel, $log . "\n" . $e->getTraceAsString() );
 			} else {
-				wfDebugLog( 'error', $log );
+				wfDebugLog( $channel, $log );
 			}
 		}
 
 		// Include all errors in the json log (surpressed errors will be flagged)
 		$json = self::jsonSerializeException( $e, false, FormatJson::ALL_OK );
 		if ( $json !== false ) {
-			wfDebugLog( 'error-json', $json, 'private' );
+			wfDebugLog( "$channel-json", $json, 'private' );
 		}
 	}
 }
-- 
2.20.1