Ticket #30294: 30294.diff

src/wp-includes/functions.php

@@ -3852 +3852 @@
  * @return bool True if $network_id is the main network, or if not running Multisite.
  */
 function is_main_network( $network_id = null ) {
-        global $wpdb;
 
-        if ( ! is_multisite() )
+        // Always return true if not a multisite installation
+        if ( ! is_multisite() ) {
                 return true;
+        }
 
         $current_network_id = (int) get_current_site()->id;
 
-        if ( ! $network_id )
+        if ( null === $network_id ) {
                 $network_id = $current_network_id;
+        }
+
         $network_id = (int) $network_id;
 
-        if ( defined( 'PRIMARY_NETWORK_ID' ) )
-                return $network_id === (int) PRIMARY_NETWORK_ID;
+        return ( $network_id === get_main_network_id() );
+}
 
-        if ( 1 === $current_network_id )
-                return $network_id === $current_network_id;
+/**
+ * Get the main network ID.
+ *
+ * @since 4.3.0
+ *
+ * @return int  
+ */
+function get_main_network_id() {
+        global $wpdb;
 
-        $primary_network_id = (int) wp_cache_get( 'primary_network_id', 'site-options' );
+        // Use constant if explicitly set.
+        if ( defined( 'MAIN_NETWORK_ID' ) ) {
+                $main_network_id = MAIN_NETWORK_ID;
 
-        if ( $primary_network_id )
-                return $network_id === $primary_network_id;
+        // If the current network has an ID of 1, assume it is the main network.
+        } elseif ( 1 === (int) get_current_site()->id ) {
+                $main_network_id = 1;
 
-        $primary_network_id = (int) $wpdb->get_var( "SELECT id FROM $wpdb->site ORDER BY id LIMIT 1" );
-        wp_cache_add( 'primary_network_id', $primary_network_id, 'site-options' );
+        // Fallback on cached value, queried from sites table.
+        } else {
+                $main_network_id = wp_cache_get( 'main_network_id', 'site-options' );
 
-        return $network_id === $primary_network_id;
+                if ( false === $main_network_id ) {
+                        $main_network_id = (int) $wpdb->get_var( "SELECT id FROM {$wpdb->site} ORDER BY id LIMIT 1" );
+                        wp_cache_add( 'main_network_id', $main_network_id, 'site-options' );
+                }
+        }
+
+        /**
+         * Filter the main network ID.
+         *
+         * @since 4.3.0
+         *
+         * @param int $main_network_id The ID of the main network.
+         */
+        return (int) apply_filters( 'get_main_network_id', $main_network_id );
 }
 
 /**