Restore new_name_timestamp index usage in UNION. Since r51907, there was no reason...

diff --git a/includes/specials/SpecialRecentchanges.php b/includes/specials/SpecialRecentchanges.php
index 4743d6e..da5d5f0 100644 (file)
--- a/includes/specials/SpecialRecentchanges.php
+++ b/includes/specials/SpecialRecentchanges.php
@@ -365,6 +365,7 @@ class SpecialRecentChanges extends IncludableSpecialPage {
                $limit = $opts['limit'];
                $namespace = $opts['namespace'];
                $invert = $opts['invert'];
+               $associated = $opts['associated'];
 
                $fields = array( $dbr->tableName( 'recentchanges' ) . '.*' ); // all rc columns
                // JOIN on watchlist for users
@@ -397,11 +398,11 @@ class SpecialRecentChanges extends IncludableSpecialPage {
 
                // Don't use the new_namespace_time timestamp index if:
                // (a) "All namespaces" selected
-               // (b) We want all pages NOT in a certain namespaces (inverted)
+               // (b) We want pages in more than one namespace (inverted/associated)
                // (c) There is a tag to filter on (use tag index instead)
                // (d) UNION + sort/limit is not an option for the DBMS
-               if( is_null( $namespace )
-                       || ( $invert && !is_null( $namespace ) )
+               if( $namespace === ''
+                       || ( $invert || $associated )
                        || $opts['tagfilter'] != ''
                        || !$dbr->unionSupportsOrderAndLimit() )
                {
@@ -420,7 +421,7 @@ class SpecialRecentChanges extends IncludableSpecialPage {
                                array(
                                        'ORDER BY' => 'rc_timestamp DESC',
                                        'LIMIT' => $limit,
-                                       'USE INDEX' => array( 'recentchanges' => 'rc_timestamp' )
+                                       'USE INDEX' => array( 'recentchanges' => 'new_name_timestamp' )
                                ),
                                $join_conds
                        );
@@ -433,7 +434,7 @@ class SpecialRecentChanges extends IncludableSpecialPage {
                                array(
                                        'ORDER BY' => 'rc_timestamp DESC',
                                        'LIMIT' => $limit,
-                                       'USE INDEX' => array( 'recentchanges' => 'rc_timestamp' )
+                                       'USE INDEX' => array( 'recentchanges' => 'new_name_timestamp' )
                                ),
                                $join_conds
                        );