From 94633ff448e9253c5503124df6748be1fc26b8e2 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Marcin=20Cie=C5=9Blak?= <saper@users.mediawiki.org>
Date: Thu, 8 Mar 2012 21:44:03 +0000
Subject: [PATCH] PostgreSQL: Improve SQL error handling

After a query error, PostgreSQL transaction is aborted
until it's terminated or the query is closed.

All further queries result in:

  ERROR: current transaction is aborted, commands ignored
  until end of transaction block

Those subsequent errors are ignored by double fault handling in
DatabaseBase::reportQueryError but they cause all localization
of error messages to fail (unable to issue queries to message
tables) and errors lke


This resulted in a broken MediaWiki screen with

  <databaseerror>
  <dberrortext>

instead of localized error message.

We need to fully reset database connection because after
pg_connection_reset() various session parameters need to
be set again (like "search_path"), otherwise tables will not be
found.

   ERROR: relation "msg_resource" does not exist
   ERROR:  relation "l10n_cache" does not exist
---
 includes/db/DatabasePostgres.php | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index 893b651011..1f1d7ed1b4 100644
--- a/includes/db/DatabasePostgres.php
+++ b/includes/db/DatabasePostgres.php
@@ -159,7 +159,6 @@ class DatabasePostgres extends DatabaseBase {
 			return;
 		}
 
-		$this->close();
 		$this->mServer = $server;
 		$port = $wgDBport;
 		$this->mUser = $user;
@@ -177,10 +176,14 @@ class DatabasePostgres extends DatabaseBase {
 		if ( $port != false && $port != '' ) {
 			$connectVars['port'] = $port;
 		}
-		$connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
+		$this->connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
+		$this->reOpen();
+	}
 
+	function reOpen() {
+		$this->close();
 		$this->installErrorHandler();
-		$this->mConn = pg_connect( $connectString );
+		$this->mConn = pg_connect( $this->connectString );
 		$phpError = $this->restoreErrorHandler();
 
 		if ( !$this->mConn ) {
@@ -253,6 +256,13 @@ class DatabasePostgres extends DatabaseBase {
 		return $this->mLastResult;
 	}
 
+	function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
+		$this->rollback( __METHOD__ );
+		$this->reOpen();
+		parent::reportQueryError( $error, $errno, $sql, $fname, $tempIgnore );
+	}
+
+
 	function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 		return $this->query( $sql, $fname, true );
 	}
-- 
2.20.1