RCFilters: Only attempt to remove tag if we can find an item for it

As noted in T198140 and T198231, removeTagByData leads us eventually to
OO.ui.mixin.GroupElement.prototype.removeItems(), which does not check if
any of the items are null values, and a change event is emitted.

This commit ensures that we can find an item for the data before attempting
to remove the tag.

Bug: T198140
Change-Id: I79a923a7b4e5f6c4d14fcce3c5855b4c56796384

diff --git a/resources/src/mediawiki.rcfilters/ui/mw.rcfilters.ui.FilterTagMultiselectWidget.js b/resources/src/mediawiki.rcfilters/ui/mw.rcfilters.ui.FilterTagMultiselectWidget.js
index d59fdfb..907c535 100644 (file)
--- a/resources/src/mediawiki.rcfilters/ui/mw.rcfilters.ui.FilterTagMultiselectWidget.js
+++ b/resources/src/mediawiki.rcfilters/ui/mw.rcfilters.ui.FilterTagMultiselectWidget.js
@@ -476,7 +476,10 @@
                        ) {
                                this.addTag( item.getName(), item.getLabel() );
                        } else {
-                               this.removeTagByData( item.getName() );
+                               // Only attempt to remove the tag if we can find an item for it (T198140, T198231)
+                               if ( this.findItemFromData( item.getName() ) !== null ) {
+                                       this.removeTagByData( item.getName() );
+                               }
                        }
                }
 
@@ -525,7 +528,10 @@
                        // Remove capsule widgets if they're not selected
                        highlightedItems.forEach( function ( filterItem ) {
                                if ( !filterItem.isSelected() ) {
-                                       this.removeTagByData( filterItem.getName() );
+                                       // Only attempt to remove the tag if we can find an item for it (T198140, T198231)
+                                       if ( this.findItemFromData( filterItem.getName() ) !== null ) {
+                                               this.removeTagByData( filterItem.getName() );
+                                       }
                                }
                        }.bind( this ) );
                }