Print chained exceptions when maintenance script fails.

PHP supports exception chaining. This patch will output the error
message and stack trace not just for the latest exceptions, but for all
exceptions in the chain, using the Exception::getPrevious() method. This
avoids the problem where aftereffects obscure the actual problem, because
only the last exception in the chain was printed.

Change-Id: If577c5c89bb3b3e5766400fff07d8cc0a2d82610

diff --git a/maintenance/doMaintenance.php b/maintenance/doMaintenance.php
index 1f1a4c7..816b385 100644 (file)
--- a/maintenance/doMaintenance.php
+++ b/maintenance/doMaintenance.php
@@ -91,7 +91,17 @@ $maintenance->checkRequiredExtensions();
 $maintenance->setAgentAndTriggers();
 
 // Do the work
-$success = $maintenance->execute();
+try {
+       $success = $maintenance->execute();
+} catch ( Exception $ex ) {
+       $success = false;
+       while ( $ex ) {
+               $cls = get_class( $ex );
+               print "$cls from line {$ex->getLine()} of {$ex->getFile()}: {$ex->getMessage()}\n";
+               print $ex->getTraceAsString() . "\n";
+               $ex = $ex->getPrevious();
+       }
+}
 
 // Potentially debug globals
 $maintenance->globals();