ha_innobase.cc, ha_innobase.h:

  Backport from 4.0.4 the bug fix of the crash when a temporary table was created inside LOCK TABLES and used

sql/ha_innobase.cc

@@ -1977,7 +1977,8 @@ convert_search_mode_to_innobase(
 		case HA_READ_AFTER_KEY:		return(PAGE_CUR_G);
 		case HA_READ_BEFORE_KEY:	return(PAGE_CUR_L);
 		case HA_READ_PREFIX:		return(PAGE_CUR_GE);
-		case HA_READ_PREFIX_LAST:	return(PAGE_CUR_LE);
+		case HA_READ_PREFIX_LAST:	ut_a(0); return(PAGE_CUR_LE);
+		        /* HA_READ_PREFIX_LAST does not yet work in InnoDB! */
 			/* the above PREFIX flags mean that the last
 			field in the key value may just be a prefix
 			of the complete fixed length field */
@@ -3413,6 +3414,47 @@ ha_innobase::reset(void)
   	return(0);
 }
 
+
+/**********************************************************************
+When we create a temporary table inside MySQL LOCK TABLES, MySQL will
+not call external_lock for the temporary table when it uses it. Instead,
+it will call this function. */
+
+int
+ha_innobase::start_stmt(
+/*====================*/
+	              /* out: 0 or error code */
+        THD*    thd)  /* in: handle to the user thread */
+{
+  row_prebuilt_t* prebuilt = (row_prebuilt_t*) innobase_prebuilt;
+  trx_t*          trx;
+
+  update_thd(thd);
+
+  trx = prebuilt->trx;
+
+  innobase_release_stat_resources(trx);
+  trx_mark_sql_stat_end(trx);
+
+  auto_inc_counter_for_this_stat = 0;
+  prebuilt->sql_stat_start = TRUE;
+  prebuilt->hint_no_need_to_fetch_extra_cols = TRUE;
+  prebuilt->read_just_key = 0;
+
+  if (prebuilt->select_lock_type == LOCK_NONE) {
+          /* This handle is for a temporary table created inside
+          this same LOCK TABLES; since MySQL does NOT call external_lock
+          in this case, we must use x-row locks inside InnoDB to be
+          prepared for an update of a row */
+
+          prebuilt->select_lock_type = LOCK_X;
+  }
+
+  thd->transaction.all.innodb_active_trans = 1;
+
+  return(0);
+}
+
 /**********************************************************************
 As MySQL will execute an external lock for every new table it uses when it
 starts to process an SQL statement, we can use this function to store the

sql/ha_innobase.h

@@ -139,6 +139,8 @@ class ha_innobase: public handler
   	int extra(enum ha_extra_function operation);
   	int reset(void);
   	int external_lock(THD *thd, int lock_type);
+	int start_stmt(THD *thd);
+
   	void position(byte *record);
   	ha_rows records_in_range(int inx,
 			   const byte *start_key,uint start_key_len,