Ticket #20920: 20920.diff

src/wp-includes/plugin.php

@@ -325 +325 @@
         global $wp_filter, $merged_filters;
 
         if ( isset( $wp_filter[ $tag ]) ) {
-                if ( false !== $priority && isset( $wp_filter[ $tag ][ $priority ] ) ) {
-                        $wp_filter[ $tag ][ $priority ] = array();
+                if ( false !== $priority ) {
+                        if ( isset( $wp_filter[ $tag ][ $priority ] ) ) {
+                                $wp_filter[ $tag ][ $priority ] = array();
+                        }
                 } else {
                         $wp_filter[ $tag ] = array();
                 }

tests/phpunit/tests/filters.php

@@ -251 +251 @@
         }
 
         /**
+         * @ticket 20920
+         */
+        function test_has_filter_after_remove_filters_on_unused_priority() {
+                $a = new MockAction();
+                $tag = rand_str();
+                $val = rand_str();
+
+                // Should not be removed
+                add_filter( $tag, array( $a, 'filter' ), 12 );
+                $this->assertTrue( has_filter( $tag ) );
+
+                remove_all_filters( $tag, 11 );
+                $this->assertTrue( has_filter( $tag ) );
+        }
+
+        /**
          * @ticket 29070
          */
         function test_has_filter_after_remove_all_filters() {