From 12f18228b421257e98fc0eff0e8cde7349b9ae7d Mon Sep 17 00:00:00 2001
From: Alexey Kopytov <Alexey.Kopytov@sun.com>
Date: Fri, 15 May 2009 12:16:00 +0400
Subject: [PATCH] Bug #44792: valgrind warning when casting from time to time

Field_time::get_time() did not initialize some members of
MYSQL_TIME which led to valgrind warnings when those members
were accessed in Protocol_simple::store_time().

It is unlikely that this bug could result in wrong data
being returned, since Field_time::get_time() initializes the
'day' member of MYSQL_TIME to 0, so the value of 'day'
in Protocol_simple::store_time() would be 0 regardless
of the values for 'year' and 'month'.
---
 mysql-test/r/type_time.result | 10 ++++++++++
 mysql-test/t/type_time.test   | 13 +++++++++++++
 sql/field.cc                  |  2 +-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/type_time.result b/mysql-test/r/type_time.result
index 96bf23109df..69dca57398f 100644
--- a/mysql-test/r/type_time.result
+++ b/mysql-test/r/type_time.result
@@ -128,3 +128,13 @@ SELECT sum(f3) FROM t1 where f2='2007-07-01 00:00:00' group by f2;
 sum(f3)
 3
 drop table t1;
+#
+# Bug #44792: valgrind warning when casting from time to time
+#
+CREATE TABLE t1 (c TIME);
+INSERT INTO t1 VALUES ('0:00:00');
+SELECT CAST(c AS TIME) FROM t1;
+CAST(c AS TIME)
+00:00:00
+DROP TABLE t1;
+End of 5.0 tests
diff --git a/mysql-test/t/type_time.test b/mysql-test/t/type_time.test
index 5fc763be7fe..5bb521601e5 100644
--- a/mysql-test/t/type_time.test
+++ b/mysql-test/t/type_time.test
@@ -77,3 +77,16 @@ insert into t1 values('2007-07-02', 1);
 insert into t1 values('2007-07-02', 2);
 SELECT sum(f3) FROM t1 where f2='2007-07-01 00:00:00' group by f2;
 drop table t1;
+
+
+--echo #
+--echo # Bug #44792: valgrind warning when casting from time to time
+--echo #
+
+CREATE TABLE t1 (c TIME);
+INSERT INTO t1 VALUES ('0:00:00');
+SELECT CAST(c AS TIME) FROM t1;
+DROP TABLE t1;
+
+
+--echo End of 5.0 tests
diff --git a/sql/field.cc b/sql/field.cc
index 99e9d7803e1..c7dd2afd934 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -4877,7 +4877,7 @@ bool Field_time::get_time(MYSQL_TIME *ltime)
     ltime->neg= 1;
     tmp=-tmp;
   }
-  ltime->day= 0;
+  ltime->year= ltime->month= ltime->day= 0;
   ltime->hour=   (int) (tmp/10000);
   tmp-=ltime->hour*10000;
   ltime->minute= (int) tmp/100;