=== modified file 'sql/handler.cc'
--- sql/handler.cc	2009-03-27 09:34:24 +0000
+++ sql/handler.cc	2009-05-18 08:17:38 +0000
@@ -2149,6 +2149,9 @@
     set_next_insert_id(compute_next_insert_id(nr, &table->in_use->variables));
 }
 
+bool handler::is_auto_inc_singleton(){
+    return true;
+}
 
 /** @brief
   Computes the largest number X:
@@ -2359,7 +2362,7 @@
       nr= compute_next_insert_id(nr-1, variables);
     }
 
-    if (table->s->next_number_keypart == 0)
+    if (!is_auto_inc_singleton() || table->s->next_number_keypart == 0)
     {
       /* We must defer the appending until "nr" has been possibly truncated */
       append= TRUE;

=== modified file 'sql/handler.h'
--- sql/handler.h	2008-12-10 20:14:50 +0000
+++ sql/handler.h	2009-05-18 08:25:58 +0000
@@ -1261,6 +1261,12 @@
   int ha_rename_partitions(const char *path);
 
   void adjust_next_insert_id_after_explicit_value(ulonglong nr);
+  /**
+     Some storage engines can perform auto increment properly even if the autoincrement column
+     is not the first column of any key.  Such storage engines should return false.
+     By default this method returns true.
+  */
+  virtual bool is_auto_inc_singleton();
   int update_auto_increment();
   void print_keydup_error(uint key_nr, const char *msg);
   virtual void print_error(int error, myf errflag);