Merge "WLFilters: fix server-side tag filtering"

[lhc/web/wiklou.git] / includes / specials / SpecialWatchlist.php

diff --git a/includes/specials/SpecialWatchlist.php b/includes/specials/SpecialWatchlist.php
index 65cc3e1..ba3cb87 100644 (file)
--- a/includes/specials/SpecialWatchlist.php
+++ b/includes/specials/SpecialWatchlist.php
@@ -386,10 +386,6 @@ class SpecialWatchlist extends ChangesListSpecialPage {
                $tables = array_merge( [ 'recentchanges', 'watchlist' ], $tables );
                $fields = array_merge( RecentChange::selectFields(), $fields );
 
                $tables = array_merge( [ 'recentchanges', 'watchlist' ], $tables );
                $fields = array_merge( RecentChange::selectFields(), $fields );
 

-               $query_options = array_merge( [
-                       'ORDER BY' => 'rc_timestamp DESC',
-                       'LIMIT' => $opts['limit']
-               ], $query_options );

                $join_conds = array_merge(
                        [
                                'watchlist' => [
                $join_conds = array_merge(
                        [
                                'watchlist' => [


@@ -426,13 +422,14 @@ class SpecialWatchlist extends ChangesListSpecialPage {
                        ], LIST_OR );
                }
 
                        ], LIST_OR );
                }
 

+               $tagFilter = $opts['tagfilter'] ? explode( '|', $opts['tagfilter'] ) : [];

                ChangeTags::modifyDisplayQuery(
                        $tables,
                        $fields,
                        $conds,
                        $join_conds,
                        $query_options,
                ChangeTags::modifyDisplayQuery(
                        $tables,
                        $fields,
                        $conds,
                        $join_conds,
                        $query_options,

-                       ''
+                       $tagFilter

                );
 
                $this->runMainQueryHook( $tables, $fields, $conds, $query_options, $join_conds, $opts );
                );
 
                $this->runMainQueryHook( $tables, $fields, $conds, $query_options, $join_conds, $opts );


@@ -441,6 +438,23 @@ class SpecialWatchlist extends ChangesListSpecialPage {
                        return false;
                }
 
                        return false;
                }
 

+               $orderByAndLimit = [
+                       'ORDER BY' => 'rc_timestamp DESC',
+                       'LIMIT' => $opts['limit']
+               ];
+               if ( in_array( 'DISTINCT', $query_options ) ) {
+                       // ChangeTags::modifyDisplayQuery() adds DISTINCT when filtering on multiple tags.
+                       // In order to prevent DISTINCT from causing query performance problems,
+                       // we have to GROUP BY the primary key. This in turn requires us to add
+                       // the primary key to the end of the ORDER BY, and the old ORDER BY to the
+                       // start of the GROUP BY
+                       $orderByAndLimit['ORDER BY'] = 'rc_timestamp DESC, rc_id DESC';
+                       $orderByAndLimit['GROUP BY'] = 'rc_timestamp, rc_id';
+               }
+               // array_merge() is used intentionally here so that hooks can, should
+               // they so desire, override the ORDER BY / LIMIT condition(s)
+               $query_options = array_merge( $orderByAndLimit, $query_options );
+

                return $dbr->select(
                        $tables,
                        $fields,
                return $dbr->select(
                        $tables,
                        $fields,