From 0bbae2475042edee792500625fe5761d3d207d5e Mon Sep 17 00:00:00 2001
From: "Justin.He/justin.he@dev3-240.dev.cn.tlan" <>
Date: Thu, 22 Mar 2007 12:16:52 +0800
Subject: [PATCH] Bug#27127, Incorrect behaviour of timestamp column with
 DEFAULT CURRENT_TIMESTAMP correct the bitmap_set_bit when a field is
 timestamp and described with default CURRENT_TIMESTAMP or on update
 CURRENT_TIMESTAMP, then it will reduce a little time cost when the field
 doesnot need to write.

---
 sql/sql_update.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 5aea05a9d39..bae1f8e9210 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -201,8 +201,10 @@ int mysql_update(THD *thd,
       table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;
     else
     {
-      bitmap_set_bit(table->write_set,
-                     table->timestamp_field->field_index);
+      if (table->timestamp_field_type == TIMESTAMP_AUTO_SET_ON_UPDATE ||
+          table->timestamp_field_type == TIMESTAMP_AUTO_SET_ON_BOTH)
+        bitmap_set_bit(table->write_set,
+                       table->timestamp_field->field_index);
     }
   }