From 9a6e05d8b9908b3b0b5bca849f5af66e7c832e7c Mon Sep 17 00:00:00 2001
From: Alexander Nozdrin <alik@sun.com>
Date: Thu, 15 Jan 2009 12:36:34 +0300
Subject: [PATCH] Backport patch for Bug#31222 (com_% global status counters
 behave randomly with mysql_change_user) to 5.0.

---
 mysql-test/r/not_embedded_server.result |  7 +++++++
 mysql-test/t/not_embedded_server.test   | 28 +++++++++++++++++++++++++
 sql/sql_class.cc                        |  4 ++++
 3 files changed, 39 insertions(+)

diff --git a/mysql-test/r/not_embedded_server.result b/mysql-test/r/not_embedded_server.result
index e471b5a3afa..edb698ade83 100644
--- a/mysql-test/r/not_embedded_server.result
+++ b/mysql-test/r/not_embedded_server.result
@@ -3,3 +3,10 @@ execute stmt1;
 Id	User	Host	db	Command	Time	State	Info
 number	root	localhost	test	Query	time	NULL	show full processlist
 deallocate prepare stmt1;
+FLUSH STATUS;
+SHOW GLOBAL STATUS LIKE 'com_select';
+Variable_name	Value
+Com_select	101
+SHOW GLOBAL STATUS LIKE 'com_select';
+Variable_name	Value
+Com_select	101
diff --git a/mysql-test/t/not_embedded_server.test b/mysql-test/t/not_embedded_server.test
index 83ec03d6706..044d8665a18 100644
--- a/mysql-test/t/not_embedded_server.test
+++ b/mysql-test/t/not_embedded_server.test
@@ -16,3 +16,31 @@ execute stmt1;
 deallocate prepare stmt1;
 
 # End of 4.1 tests
+
+#
+# Bug#31222: com_% global status counters behave randomly with
+# mysql_change_user.
+#
+
+FLUSH STATUS;
+
+--disable_result_log
+--disable_query_log
+
+let $i = 100;
+
+while ($i)
+{
+  dec $i;
+
+  SELECT 1;
+}
+
+--enable_query_log
+--enable_result_log
+
+SHOW GLOBAL STATUS LIKE 'com_select';
+
+--change_user
+
+SHOW GLOBAL STATUS LIKE 'com_select';
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 883291ec460..91c0aa66761 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -391,6 +391,10 @@ void THD::init_for_queries()
 
 void THD::change_user(void)
 {
+  pthread_mutex_lock(&LOCK_status);
+  add_to_status(&global_status_var, &status_var);
+  pthread_mutex_unlock(&LOCK_status);
+
   cleanup();
   cleanup_done= 0;
   init();