Ticket #32154: 32154.02.patch

wp-admin/includes/upgrade.php

@@ -1208 +1208 @@
                 add_site_option( 'siteurl', '' );
 
         // 3.0 screen options key name changes.
-        if ( is_main_site() && !defined('DO_NOT_UPGRADE_GLOBAL_TABLES') ) {
+        if ( wp_can_upgrade_global_tables() ) {
                 $sql = "DELETE FROM $wpdb->usermeta
                         WHERE meta_key LIKE %s
                         OR meta_key LIKE %s
@@ -1243 +1243 @@
 function upgrade_330() {
         global $wp_current_db_version, $wpdb, $wp_registered_widgets, $sidebars_widgets;
 
-        if ( $wp_current_db_version < 19061 && is_main_site() && ! defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) {
+        if ( $wp_current_db_version < 19061 && wp_can_upgrade_global_tables() ) {
                 $wpdb->query( "DELETE FROM $wpdb->usermeta WHERE meta_key IN ('show_admin_bar_admin', 'plugins_last_view')" );
         }
 
@@ -1324 +1324 @@
                 $wpdb->show_errors();
         }
 
-        if ( $wp_current_db_version < 20022 && is_main_site() && ! defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) {
+        if ( $wp_current_db_version < 20022 && wp_can_upgrade_global_tables() ) {
                 $wpdb->query( "DELETE FROM $wpdb->usermeta WHERE meta_key = 'themes_last_view'" );
         }
 
@@ -1348 +1348 @@
         if ( $wp_current_db_version < 22006 && $wpdb->get_var( "SELECT link_id FROM $wpdb->links LIMIT 1" ) )
                 update_option( 'link_manager_enabled', 1 ); // Previously set to 0 by populate_options()
 
-        if ( $wp_current_db_version < 21811 && is_main_site() && ! defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) {
+        if ( $wp_current_db_version < 21811 && wp_can_upgrade_global_tables() ) {
                 $meta_keys = array();
                 foreach ( array_merge( get_post_types(), get_taxonomies() ) as $name ) {
                         if ( false !== strpos( $name, '-' ) )
@@ -1564 +1564 @@
 
         // 4.2
         if ( $wp_current_db_version < 31351 && $wpdb->charset === 'utf8mb4' ) {
-                if ( ! ( defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) && DO_NOT_UPGRADE_GLOBAL_TABLES ) ) {
-                        $wpdb->query( "ALTER TABLE $wpdb->usermeta DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
-                        $wpdb->query( "ALTER TABLE $wpdb->site DROP INDEX domain, ADD INDEX domain(domain(140),path(51))" );
-                        $wpdb->query( "ALTER TABLE $wpdb->sitemeta DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
-                        $wpdb->query( "ALTER TABLE $wpdb->signups DROP INDEX domain, ADD INDEX domain(domain(140),path(51))" );
+                if ( wp_can_upgrade_global_tables() ) {
+                        $wpdb->query( "ALTER TABLE `{$wpdb->usermeta}` DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
+                        $wpdb->query( "ALTER TABLE `{$wpdb->site}` DROP INDEX domain, ADD INDEX domain(domain(140),path(51))" );
+                        $wpdb->query( "ALTER TABLE `{$wpdb->sitemeta}` DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
+                        $wpdb->query( "ALTER TABLE `{$wpdb->signups}` DROP INDEX domain, ADD INDEX domain(domain(140),path(51))" );
 
                         $tables = $wpdb->tables( 'global' );
 
@@ -1870 +1870 @@
 
         $global_tables = $wpdb->tables( 'global' );
         foreach ( $cqueries as $table => $qry ) {
-                // Upgrade global tables only for the main site. Don't upgrade at all if DO_NOT_UPGRADE_GLOBAL_TABLES is defined.
-                if ( in_array( $table, $global_tables ) && ( !is_main_site() || defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) ) {
+                // Upgrade global tables only for the main site. Don't upgrade at all if conditions are not optimal.
+                if ( in_array( $table, $global_tables ) && ! wp_can_upgrade_global_tables() ) {
                         unset( $cqueries[ $table ], $for_update[ $table ] );
                         continue;
                 }
@@ -2380 +2380 @@
         }
 
         // Multisite schema upgrades.
-        if ( $wp_current_db_version < 25448 && is_multisite() && ! defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) && is_main_network() ) {
+        if ( $wp_current_db_version < 25448 && wp_can_upgrade_global_tables() ) {
 
                 // Upgrade verions prior to 3.7
                 if ( $wp_current_db_version < 25179 ) {
@@ -2403 +2403 @@
 
         // Upgrade versions prior to 4.2.
         if ( $wp_current_db_version < 31351 ) {
-                if ( ! is_multisite() ) {
+                if ( upgrade_global_tables() ) {
                         $wpdb->query( "ALTER TABLE $wpdb->usermeta DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
                 }
                 $wpdb->query( "ALTER TABLE $wpdb->terms DROP INDEX slug, ADD INDEX slug(slug(191))" );
@@ -2438 +2438 @@
         dbDelta( $ms_queries );
 }
 endif;
+
+/**
+ * Can global tables be upgraded?
+ * 
+ * This function performs a series of checks to ensure the environment allows
+ * for the safe upgrading of global WordPress database tables. It is necessary
+ * because global tables will commonly grow to millions of rows on large
+ * installations, and the ability to control their upgrade routines can be
+ * critical to the operation of large networks.
+ *
+ * In a future iteration, this function may use `wp_is_large_network()` to more-
+ * intelligently prevent global table upgrades. Until then, we make sure
+ * WordPress is on the main site of the main network, to avoid running queries
+ * more than once in multi-site or multi-network environments.
+ *
+ * @since WordPress 4.3.0
+ *
+ * @return boolean
+ */
+function wp_can_upgrade_global_tables() {
+
+        // Assume global tables should be updated
+        $retval = true;
+
+        // Return false early if explicitly not upgrading
+        if ( defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) {
+                return false;
+        }
+
+        // Set to false if not on main network (does not matter if not multi-network)
+        if ( ! is_main_network() ) {
+                $retval = false;
+        }
+
+        // Set to false if not on main site of current network (does not matter if not multi-site)
+        if ( ! is_main_site() ) {
+                $retval = false;
+        }
+
+        return (bool) apply_filters( 'wp_can_upgrade_global_tables', $retval );
+}