X-Git-Url: https://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=blobdiff_plain;f=includes%2Fspecials%2FSpecialRecentchangeslinked.php;h=fee336e435e95f8548b3d88ac66e2910a56bf7f0;hp=873285b8c763a77f4703acda21d3b24fc03a9994;hb=24ebca2251f94a20acee53e583d65aa7fac2c15d;hpb=55043101b2a89ea1e811b6d35e415f57ed0bf41d

diff --git a/includes/specials/SpecialRecentchangeslinked.php b/includes/specials/SpecialRecentchangeslinked.php
index 873285b8c7..fee336e435 100644
--- a/includes/specials/SpecialRecentchangeslinked.php
+++ b/includes/specials/SpecialRecentchangeslinked.php
@@ -50,8 +50,8 @@ class SpecialRecentChangesLinked extends SpecialRecentChanges {
 	 * @inheritdoc
 	 */
 	protected function doMainQuery( $tables, $select, $conds, $query_options,
-		$join_conds, FormOptions $opts ) {
-
+		$join_conds, FormOptions $opts
+	) {
 		$target = $opts['target'];
 		$showlinkedto = $opts['showlinkedto'];
 		$limit = $opts['limit'];
@@ -103,15 +103,33 @@ class SpecialRecentChangesLinked extends SpecialRecentChanges {
 			$join_conds['page'] = [ 'LEFT JOIN', 'rc_cur_id=page_id' ];
 			$select[] = 'page_latest';
 		}
+
+		$tagFilter = $opts['tagfilter'] ? explode( '|', $opts['tagfilter'] ) : [];
 		ChangeTags::modifyDisplayQuery(
 			$tables,
 			$select,
 			$conds,
 			$join_conds,
 			$query_options,
-			$opts['tagfilter']
+			$tagFilter
 		);
 
+		if ( $dbr->unionSupportsOrderAndLimit() ) {
+			if ( count( $tagFilter ) > 1 ) {
+				// ChangeTags::modifyDisplayQuery() will have added DISTINCT.
+				// To prevent this from causing query performance problems, we need to add
+				// a GROUP BY, and add rc_id to the ORDER BY.
+				$order = [
+					'GROUP BY' => 'rc_timestamp, rc_id',
+					'ORDER BY' => 'rc_timestamp DESC, rc_id DESC'
+				];
+			} else {
+				$order = [ 'ORDER BY' => 'rc_timestamp DESC' ];
+			}
+		} else {
+			$order = [];
+		}
+
 		if ( !$this->runMainQueryHook( $tables, $select, $conds, $query_options, $join_conds,
 			$opts )
 		) {
@@ -181,12 +199,6 @@ class SpecialRecentChangesLinked extends SpecialRecentChanges {
 				}
 			}
 
-			if ( $dbr->unionSupportsOrderAndLimit() ) {
-				$order = [ 'ORDER BY' => 'rc_timestamp DESC' ];
-			} else {
-				$order = [];
-			}
-
 			$query = $dbr->selectSQLText(
 				array_merge( $tables, [ $link_table ] ),
 				$select,