From d0d539e6bae1d5b333828ad346eadef3399f5fb1 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Gerg=C5=91=20Tisza?= <gtisza@wikimedia.org>
Date: Sun, 24 May 2015 11:30:10 +0000
Subject: [PATCH] Add a hook for reporting exceptions

Bug: T100141
Change-Id: I893f8b93e09f9ef70beef46922d304fdb3600b78
---
 RELEASE-NOTES-1.26                        | 1 +
 docs/hooks.txt                            | 5 +++++
 includes/exception/MWExceptionHandler.php | 7 ++++++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/RELEASE-NOTES-1.26 b/RELEASE-NOTES-1.26
index af9e9d2b64..d1458bd399 100644
--- a/RELEASE-NOTES-1.26
+++ b/RELEASE-NOTES-1.26
@@ -15,6 +15,7 @@ production.
   "tag-<id>" interface message.
 * ':' (colon) is now invalid in usernames for new accounts. Existing accounts
   are not affected.
+* Added a new hook, 'LogException', to log exceptions in nonstandard ways.
 
 ==== External libraries ====
 
diff --git a/docs/hooks.txt b/docs/hooks.txt
index 131986a7a6..8e9223b578 100644
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -1842,6 +1842,11 @@ $param: Associative Array with the following additional options:
     "&lt;div ...>$1&lt;/div>").
   - flags Integer display flags (NO_ACTION_LINK,NO_EXTRA_USER_LINKS)
 
+'LogException': Called before an exception (or PHP error) is logged. This is meant for integration
+with external error aggregation services; returning false will NOT prevent logging.
+$e: The exception (in case of a plain old PHP error, a wrapping ErrorException)
+$suppressed: true if the error was suppressed via error_reporting()/wfSuppressWarnings()
+
 'LoginAuthenticateAudit': A login attempt for a valid user account either
 succeeded or failed. No return data is accepted; this hook is for auditing only.
 $user: the User object being authenticated against
diff --git a/includes/exception/MWExceptionHandler.php b/includes/exception/MWExceptionHandler.php
index c50b6c8c2b..a58705f64e 100644
--- a/includes/exception/MWExceptionHandler.php
+++ b/includes/exception/MWExceptionHandler.php
@@ -486,6 +486,8 @@ TXT;
 			if ( $json !== false ) {
 				wfDebugLog( 'exception-json', $json, 'private' );
 			}
+
+			Hooks::run( 'LogException', array( $e, false ) );
 		}
 	}
 
@@ -501,7 +503,8 @@ TXT;
 
 		// The set_error_handler callback is independent from error_reporting.
 		// Filter out unwanted errors manually (e.g. when wfSuppressWarnings is active).
-		if ( ( error_reporting() & $e->getSeverity() ) !== 0 ) {
+		$suppressed = ( error_reporting() & $e->getSeverity() ) === 0;
+		if ( !$suppressed ) {
 			$log = self::getLogMessage( $e );
 			if ( $wgLogExceptionBacktrace ) {
 				wfDebugLog( $channel, $log . "\n" . $e->getTraceAsString() );
@@ -515,5 +518,7 @@ TXT;
 		if ( $json !== false ) {
 			wfDebugLog( "$channel-json", $json, 'private' );
 		}
+
+		Hooks::run( 'LogException', array( $e, $suppressed ) );
 	}
 }
-- 
2.20.1