Changeset 31349 for trunk/src/wp-admin/includes/upgrade.php

Timestamp:

02/06/2015 04:50:19 AM (10 years ago)

Author:

pento

Message:

WPDB: If a site is using the utf8 charset, and their version of MySQL supports utf8mb4, auto-upgrade them to utf8mb4.

This patch also resizes some indexes, to allow for the 767 byte index size limit in standard MySQL installs.

See #21212

File:

• trunk/src/wp-admin/includes/upgrade.php (modified) (5 diffs)

trunk/src/wp-admin/includes/upgrade.php

@@ -519 +519 @@
     if ( $wp_current_db_version < 29630 )
         upgrade_400();
+
+    if ( $wp_current_db_version < 31349 )
+        upgrade_420();
 
     maybe_disable_link_manager();
@@ -1408 +1411 @@
 
 /**
+ * Execute changes made in WordPress 4.2.0.
+ *
+ * @since 4.2.0
+ */
+function upgrade_420() {
+    global $wp_current_db_version, $wpdb;
+
+    if ( $wp_current_db_version < 31349 && $wpdb->charset === 'utf8mb4' ) {
+        if ( is_multisite() ) {
+            $tables = $wpdb->tables( 'blog' );
+        } else {
+            $tables = $wpdb->tables( 'all' );
+        }
+
+        foreach ( $tables as $table ) {
+            maybe_convert_table_to_utf8mb4( $table );
+        }
+    }
+}
+
+/**
  * Executes network-level upgrade routines.
  *
@@ -1503 +1527 @@
         }
     }
+
+    // 4.2
+    if ( $wp_current_db_version < 31349 && $wpdb->charset === 'utf8mb4' ) {
+        if ( ! ( defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) && DO_NOT_UPGRADE_GLOBAL_TABLES ) ) {
+            $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' );
+
+            foreach ( $tables as $table ) {
+                maybe_convert_table_to_utf8mb4( $table );
+            }
+        }
+    }
 }
 
@@ -1606 +1645 @@
     }
     return false;
+}
+
+/**
+ * If a table only contains utf8 or utf8mb4 columns, convert it to utf8mb4.
+ *
+ * @since 4.2.0
+ *
+ * @param string $table The table to convert.
+ * @return bool true if the table was converted, false if it wasn't.
+ */
+function maybe_convert_table_to_utf8mb4( $table ) {
+    global $wpdb;
+
+    $results = $wpdb->get_results( "SHOW FULL COLUMNS FROM `$table`" );
+    if ( ! $results ) {
+        return false;
+    }
+
+    $has_utf8 = false;
+    foreach ( $results as $column ) {
+        if ( $column->Collation ) {
+            if ( 'utf8' === $column->Collation ) {
+                $has_utf8 = true;
+            } elseif ( 'utf8mb4' !== $column->Collation ) {
+                // Don't upgrade tables that have non-utf8 columns.
+                return false;
+            }
+        }
+    }
+
+    if ( ! $has_utf8 ) {
+        // Don't bother upgrading tables that don't have utf8 columns.
+        return false;
+    }
+
+    return $wpdb->query( "ALTER TABLE $table CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci" );
 }
 
@@ -2285 +2360 @@
         $wpdb->query( "ALTER TABLE $wpdb->terms DROP INDEX slug" );
     }
+
+    // Upgrade versions prior to 4.2.
+    if ( $wp_current_db_version < 31349 ) {
+        // So that we can change tables to utf8mb4, we need to shorten the index lengths to less than 767 bytes
+        $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))" );
+        $wpdb->query( "ALTER TABLE $wpdb->terms DROP INDEX name, ADD INDEX name(name(191))" );
+        $wpdb->query( "ALTER TABLE $wpdb->commentmeta DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
+        $wpdb->query( "ALTER TABLE $wpdb->postmeta DROP INDEX meta_key, ADD INDEX meta_key(meta_key(191))" );
+        $wpdb->query( "ALTER TABLE $wpdb->posts DROP INDEX post_name, ADD INDEX post_name(post_name(191))" );
+    }
 }