1 files changed, 12 insertions, 6 deletions
diff --git a/lib/schema.php b/lib/schema.php
index 9f2899ba8..4feb11a87 100644
--- a/lib/schema.php
+++ b/lib/schema.php
@@ -493,12 +493,6 @@ class Schema
         $uniques = $this->diffArrays($old, $def, 'unique keys');
         $indexes = $this->diffArrays($old, $def, 'indexes');
 
-        $total = $fields['count'] + $uniques['count'] + $indexes['count'];
-        if ($total == 0) {
-            // nothing to do
-            return array();
-        }
-
         // For efficiency, we want this all in one
         // query, instead of using our methods.
 
@@ -527,6 +521,13 @@ class Schema
             $this->appendAlterAddUnique($phrase, $keyName, $def['unique keys'][$keyName]);
         }
 
+        $this->appendAlterExtras($phrase, $tableName);
+
+        if (count($phrase) == 0) {
+            // nothing to do
+            return array();
+        }
+
         $sql = 'ALTER TABLE ' . $tableName . ' ' . implode(",\n", $phrase);
 
         return array($sql);
@@ -625,6 +626,11 @@ class Schema
         $phrase[] = 'DROP CONSTRAINT ' . $keyName;
     }
 
+    function appendAlterExtras(array &$phrase, $tableName)
+    {
+        // no-op
+    }
+
     /**
      * Quote a db/table/column identifier if necessary.
      *