From: jenkins-bot <jenkins-bot@gerrit.wikimedia.org>
Date: Mon, 13 Jan 2014 03:15:46 +0000 (+0000)
Subject: Merge "Changed FOR UPDATE handling in Postgresql"
X-Git-Tag: 1.31.0-rc.0~17271
X-Git-Url: https://git.cyclocoop.org/%27.WWW_URL.%27admin/?a=commitdiff_plain;h=da39646ddc98bce9cc1243ab217428e449b5d9ae;hp=0998c41943459bec74b95397976f6fed25b99c4a;p=lhc%2Fweb%2Fwiklou.git

Merge "Changed FOR UPDATE handling in Postgresql"
---

diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index 7f0ea97635..cb671d8ddb 100644
--- a/includes/db/DatabasePostgres.php
+++ b/includes/db/DatabasePostgres.php
@@ -819,6 +819,29 @@ __INDEXATTR__;
 		return $res->numRows() > 0;
 	}
 
+	/**
+	 * Change the FOR UPDATE option as necessary based on the join conditions. Then pass
+	 * to the parent function to get the actual SQL text.
+	 *
+	 * In Postgres when using FOR UPDATE, only the main table and tables that are inner joined
+	 * can be locked. That means tables in an outer join cannot be FOR UPDATE locked. Trying to do
+	 * so causes a DB error. This wrapper checks which tables can be locked and adjusts it accordingly.
+	 */
+	function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__, $options = array(), $join_conds = array() ) {
+		$forUpdateKey = array_search( 'FOR UPDATE', $options );
+		if ( $forUpdateKey !== false && $join_conds ) {
+			unset( $options[$forUpdateKey] );
+
+			foreach ( $join_conds as $table => $join_cond ) {
+				if ( 0 === preg_match( '/^(?:LEFT|RIGHT|FULL)(?: OUTER)? JOIN$/i', $join_cond[0] ) ) {
+					$options['FOR UPDATE'][] = $table;
+				}
+			}
+		}
+
+		return parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
+	}
+
 	/**
 	 * INSERT wrapper, inserts an array into a table
 	 *
@@ -1537,9 +1560,12 @@ SQL;
 		//		: false );
 		//}
 
-		if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
+		if ( isset( $options['FOR UPDATE'] ) ) {
+			$postLimitTail .= ' FOR UPDATE OF ' . implode( ', ', $options['FOR UPDATE'] );
+		} else if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
 			$postLimitTail .= ' FOR UPDATE';
 		}
+
 		if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
 			$startOpts .= 'DISTINCT';
 		}