Changeset 37525 for trunk/src/wp-admin/includes/upgrade.php

Timestamp:

05/23/2016 08:35:59 AM (8 years ago)

Author:

pento

Message:

Database: dbDelta() will no longer try to downgrade the size of TEXT and BLOB columns.

When upgrading to utf8mb4, TEXT fields will be upgraded to MEDIUMTEXT (and likewise for all other *TEXT and *BLOB fields). This is to allow for the additional space requirements of utf8mb4.

On the subsequent upgrade, after the utf8mb4 upgrade, dbDelta() would try and downgrade the fields to their original size again. At best, this it a waste of time, at worst, this could truncate any data larger than the original size. There's no harm in leaving them at their original size, so let's do that.

Fixes #36748.

File:

• trunk/src/wp-admin/includes/upgrade.php (modified) (2 diffs)

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

@@ -2155 +2155 @@
     $iqueries = apply_filters( 'dbdelta_insert_queries', $iqueries );
 
+    $text_fields = array( 'tinytext', 'text', 'mediumtext', 'longtext' );
+    $blob_fields = array( 'tinyblob', 'blob', 'mediumblob', 'longblob' );
+
     $global_tables = $wpdb->tables( 'global' );
     foreach ( $cqueries as $table => $qry ) {
@@ -2224 +2227 @@
                 // Is actual field type different from the field type in query?
                 if ($tablefield->Type != $fieldtype) {
+                    $do_change = true;
+                    if ( in_array( strtolower( $fieldtype ), $text_fields ) && in_array( strtolower( $tablefield->Type ), $text_fields ) ) {
+                        if ( array_search( strtolower( $fieldtype ), $text_fields ) < array_search( strtolower( $tablefield->Type ), $text_fields ) ) {
+                            $do_change = false;
+                        }
+                    }
+
+                    if ( in_array( strtolower( $fieldtype ), $blob_fields ) && in_array( strtolower( $tablefield->Type ), $blob_fields ) ) {
+                        if ( array_search( strtolower( $fieldtype ), $blob_fields ) < array_search( strtolower( $tablefield->Type ), $blob_fields ) ) {
+                            $do_change = false;
+                        }
+                    }
+
+                    if ( $do_change ) {
                     // Add a query to change the column type
-                    $cqueries[] = "ALTER TABLE {$table} CHANGE COLUMN {$tablefield->Field} " . $cfields[strtolower($tablefield->Field)];
-                    $for_update[$table.'.'.$tablefield->Field] = "Changed type of {$table}.{$tablefield->Field} from {$tablefield->Type} to {$fieldtype}";
+                        $cqueries[] = "ALTER TABLE {$table} CHANGE COLUMN {$tablefield->Field} " . $cfields[strtolower($tablefield->Field)];
+                        $for_update[$table.'.'.$tablefield->Field] = "Changed type of {$table}.{$tablefield->Field} from {$tablefield->Type} to {$fieldtype}";
+                    }
                 }