From 57a1e7b2705798b9ee8c01339839d5c7895542fa Mon Sep 17 00:00:00 2001
From: Reedy <reedy@wikimedia.org>
Date: Mon, 21 Nov 2016 21:32:30 +0000
Subject: [PATCH] Replace wgShowExceptionDetails with wgShowDBErrorBacktrace on
 db errors

Bug: T148957
Change-Id: I8891369156547e8931463a2fd55995cfa9e98ee7
---
 includes/exception/MWExceptionRenderer.php | 27 ++++++++++++++++------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/includes/exception/MWExceptionRenderer.php b/includes/exception/MWExceptionRenderer.php
index 8fdc417c1e..873e8f423f 100644
--- a/includes/exception/MWExceptionRenderer.php
+++ b/includes/exception/MWExceptionRenderer.php
@@ -61,8 +61,7 @@ class MWExceptionRenderer {
 						"\nBacktrace:\n" . MWExceptionHandler::getRedactedTraceAsString( $eNew );
 				} else {
 					$message .= "Exception caught inside exception handler.\n\n" .
-						"Set \$wgShowExceptionDetails = true; at the bottom of LocalSettings.php " .
-						"to show detailed debugging information.";
+						self::getShowBacktraceError( $e );
 				}
 				$message .= "\n";
 			} else {
@@ -226,9 +225,7 @@ class MWExceptionRenderer {
 					$logId,
 					MWExceptionHandler::getURL()
 				) . "</div>\n" .
-			"<!-- Set \$wgShowExceptionDetails = true; " .
-			"at the bottom of LocalSettings.php to show detailed " .
-			"debugging information. -->";
+				"<!-- " . wordwrap( self::getShowBacktraceError( $e ), 50 ) . " -->";
 		}
 
 		return $html;
@@ -262,8 +259,7 @@ class MWExceptionRenderer {
 				"\nBacktrace:\n" .
 				MWExceptionHandler::getRedactedTraceAsString( $e ) . "\n";
 		} else {
-			return "Set \$wgShowExceptionDetails = true; " .
-				"in LocalSettings.php to show detailed debugging information.\n";
+			return self::getShowBacktraceError( $e );
 		}
 	}
 
@@ -280,6 +276,23 @@ class MWExceptionRenderer {
 		);
 	}
 
+	/**
+	 * @param Exception|Throwable $e
+	 * @return string
+	 */
+	private static function getShowBacktraceError( $e ) {
+		global $wgShowExceptionDetails, $wgShowDBErrorBacktrace;
+		$vars = [];
+		if ( !$wgShowExceptionDetails ) {
+			$vars[] = '$wgShowExceptionDetails = true;';
+		}
+		if ( $e instanceof DBError && !$wgShowDBErrorBacktrace ) {
+			$vars[] = '$wgShowDBErrorBacktrace = true;';
+		}
+		$vars = implode( ' and ', $vars );
+		return "Set $vars at the bottom of LocalSettings.php to show detailed debugging information";
+	}
+
 	/**
 	 * @return bool
 	 */
-- 
2.20.1