Make $wgShowExceptionDetails=false more feasible for production

* Make the HTML error message prettier, with a nice red box and
  instructions to modify LocalSettings.php hidden in an HTML comment.
* Show the exception class name, since that's pretty safe.
* Show a random "log ID" to the user, and also send it to the exception
  log, to allow easier log correlation.
* Optionally send backtraces to the error log, enabled by default.

Change-Id: Ie92e46032b3d194c4217119567847a38a53be577

diff --git a/RELEASE-NOTES-1.20 b/RELEASE-NOTES-1.20
index 4920509..78c7c95 100644 (file)
--- a/RELEASE-NOTES-1.20
+++ b/RELEASE-NOTES-1.20
@@ -54,6 +54,8 @@ upgrade PHP if you have not done so prior to upgrading MediaWiki.
 * (bug 22887) Add warning and tracking category for preprocessor errors
 * (bug 31704) Allow selection of associated namespace on the watchlist
 * (bug 5445) Now remove autoblocks when a user is unblocked.
+* Added $wgLogExceptionBacktrace, on by default, to allow logging of exception
+  backtraces.
 
 === Bug fixes in 1.20 ===
 * (bug 30245) Use the correct way to construct a log page title.

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index d05f020..7084bc6 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -4141,6 +4141,11 @@ $wgShowExceptionDetails = false;
  */
 $wgShowDBErrorBacktrace = false;
 
+/**
+ * If true, send the exception backtrace to the error log
+ */
+$wgLogExceptionBacktrace = true;
+
 /**
  * Expose backend server host names through the API and various HTML comments
  */

diff --git a/includes/Exception.php b/includes/Exception.php
index 539d483..f7b6b96 100644 (file)
--- a/includes/Exception.php
+++ b/includes/Exception.php
@@ -15,6 +15,8 @@
  * @ingroup Exception
  */
 class MWException extends Exception {
+       var $logId;
+
        /**
         * Should the exception use $wgOut to output the error ?
         * @return bool
@@ -111,9 +113,14 @@ class MWException extends Exception {
                                '</p><p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) ) .
                                "</p>\n";
                } else {
-                       return "<p>Set <b><tt>\$wgShowExceptionDetails = true;</tt></b> " .
+                       return 
+                               "<div class=\"errorbox\">" .
+                               '[' . $this->getLogId() . '] ' .
+                               gmdate( 'Y-m-d H:i:s' ) . 
+                               ": Fatal exception of type " . get_class( $this ) . "</div>\n" .
+                               "<!-- Set \$wgShowExceptionDetails = true; " .
                                "at the bottom of LocalSettings.php to show detailed " .
-                               "debugging information.</p>";
+                               "debugging information. -->";
                }
        }
 
@@ -142,6 +149,13 @@ class MWException extends Exception {
                return $this->msg( 'internalerror', "Internal error" );
        }
 
+       function getLogId() {
+               if ( $this->logId === null ) {
+                       $this->logId = wfRandomString( 8 );
+               }
+               return $this->logId;
+       }
+
        /**
         * Return the requested URL and point to file and line number from which the
         * exception occured
@@ -151,6 +165,7 @@ class MWException extends Exception {
        function getLogMessage() {
                global $wgRequest;
 
+               $id = $this->getLogId();
                $file = $this->getFile();
                $line = $this->getLine();
                $message = $this->getMessage();
@@ -164,7 +179,7 @@ class MWException extends Exception {
                        $url = '[no req]';
                }
 
-               return "$url   Exception from line $line of $file: $message";
+               return "[$id] $url   Exception from line $line of $file: $message";
        }
 
        /** Output the exception report using HTML */
@@ -198,10 +213,15 @@ class MWException extends Exception {
         * It will be either HTML or plain text based on isCommandLine().
         */
        function report() {
+               global $wgLogExceptionBacktrace;
                $log = $this->getLogMessage();
 
                if ( $log ) {
-                       wfDebugLog( 'exception', $log );
+                       if ( $wgLogExceptionBacktrace ) {
+                               wfDebugLog( 'exception', $log . "\n" . $this->getTraceAsString() . "\n" );
+                       } else {
+                               wfDebugLog( 'exception', $log );
+                       }
                }
 
                if ( defined( 'MW_API' ) ) {