Ticket #29684: 29684.19.diff

src/wp-includes/class-wp-network.php

@@ -219 +219 @@
                  *
                  * @since 4.9.0
                  *
-                 * @param int|null $main_site_id If a positive integer is returned, it is interpreted as the main site ID.
-                 * @param int $network_id The ID of the network for which the main site was detected.
+                 * @param int|null   $main_site_id If a positive integer is returned, it is interpreted as the main site ID.
+                 * @param WP_Network $network      The network object for which the main site was detected.
                  */
-                $main_site_id = (int) apply_filters( 'pre_get_main_site_id', null, $this->id );
+                $main_site_id = (int) apply_filters( 'pre_get_main_site_id', null, $this );
                 if ( 0 < $main_site_id ) {
                         return $main_site_id;
                 }

tests/phpunit/tests/multisite/getMainSiteId.php

@@ -107 +107 @@
         }
 
         /**
+         * @ticket 29684
+         */
+        public function test_get_main_site_id_filtered_depending_on_network() {
+                add_filter( 'pre_get_main_site_id', array( $this, 'filter_get_main_site_id_depending_on_network' ), 10, 2 );
+                $result = get_main_site_id( self::$network_ids['wordpress.org/'] );
+
+                $this->assertSame( 333, $result );
+        }
+
+        public function filter_get_main_site_id_depending_on_network( $main_site_id, $network ) {
+                // Override main site ID for a specific network for the test.
+                if ( $network->id === (int) self::$network_ids['wordpress.org/'] ) {
+                        return 333;
+                }
+
+                return $main_site_id;
+        }
+
+        /**
          * @ticket 41936
          */
         public function test_get_main_site_id_with_property_value() {