Merge "Changed FOR UPDATE handling in Postgresql"

diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index 7f0ea97..cb671d8 100644 (file)
--- 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';
                }