Ticket #12891: relation-or.3.diff

wp-includes/taxonomy.php

@@ -526 +526 @@
         $join = '';
         $where = '';
         $i = 0;
+
+        if ( isset( $tax_query['relation'] ) && strtoupper( $tax_query['relation'] ) == 'OR' ) {
+                $relation = 'OR';
+        } else {
+                $relation = 'AND';
+        }
+
         foreach ( $tax_query as $query ) {
+                if ( ! is_array( $query ) )
+                        continue;
+
                 extract( wp_parse_args( $query, array(
                         'taxonomy' => array(),
                         'terms' => array(),
@@ -566 +576 @@
                 }
 
                 if ( 'IN' == $operator ) {
-                        if ( empty( $terms ) )
-                                return array( 'join' => '', 'where' => ' AND 0 = 1');
 
+                        if ( empty( $terms ) ) {
+                                if ( 'OR' == $relation )
+                                        continue;
+                                else
+                                        return array( 'join' => '', 'where' => ' AND 0 = 1' );
+                        }
+
                         $terms = implode( ',', $terms );
 
                         $alias = $i ? 'tt' . $i : $wpdb->term_relationships;
@@ -577 +592 @@
                         $join .= $i ? " AS $alias" : '';
                         $join .= " ON ($primary_table.$primary_id_column = $alias.object_id)";
 
-                        $where .= " AND $alias.term_taxonomy_id $operator ($terms)";
+                        if ( $i )
+                                $where .= " $relation ";
 
-                        $i++;
+                        $where .= "$alias.term_taxonomy_id $operator ($terms)";
                 }
                 elseif ( 'NOT IN' == $operator ) {
+
                         if ( empty( $terms ) )
                                 continue;
 
                         $terms = implode( ',', $terms );
 
-                        $where .= " AND $primary_table.$primary_id_column NOT IN (
-                                SELECT object_id 
-                                FROM $wpdb->term_relationships 
+                        if ( $i )
+                                $where .= " $relation ";
+
+                        $where .= "$primary_table.$primary_id_column NOT IN (
+                                SELECT object_id
+                                FROM $wpdb->term_relationships
                                 WHERE term_taxonomy_id IN ($terms)
                         )";
                 }
+
+                $i++;
         }
 
+        $where = ' AND ( ' . $where . ' )';
+
         return compact( 'join', 'where' );
 }