From a4e5902039db10e5661c8475790aff84e67dff09 Mon Sep 17 00:00:00 2001
From: Alexander Barkov <bar@mariadb.org>
Date: Mon, 28 Sep 2015 19:12:05 +0400
Subject: [PATCH] MDEV-8862 Wrong field type for MAX(COALESCE(datetime_column))

---
 mysql-test/r/type_time.result | 9 +++++++++
 mysql-test/t/type_time.test   | 8 ++++++++
 sql/item_func.cc              | 4 +++-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/type_time.result b/mysql-test/r/type_time.result
index 59de00fa416..bdcffc8d824 100644
--- a/mysql-test/r/type_time.result
+++ b/mysql-test/r/type_time.result
@@ -1206,5 +1206,14 @@ Warning	1292	Incorrect time value: '9000000' for column 'b' at row 4
 Warning	1292	Incorrect time value: '9000000' for column 'c' at row 4
 DROP TABLE t1;
 #
+# MDEV-8862 Wrong field type for MAX(COALESCE(datetime_column))
+#
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('10:10:10'),('10:20:30');
+SELECT MAX(a), MAX(COALESCE(a)) FROM t1;
+MAX(a)	MAX(COALESCE(a))
+10:20:30	10:20:30
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #
diff --git a/mysql-test/t/type_time.test b/mysql-test/t/type_time.test
index b257aa4f455..27679b9ec5a 100644
--- a/mysql-test/t/type_time.test
+++ b/mysql-test/t/type_time.test
@@ -715,6 +715,14 @@ INSERT INTO t1 VALUES (9000000,9000000,9000000);
 SELECT a, TIME(a),TIME(b),TIME(c) FROM t1 ORDER BY a;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-8862 Wrong field type for MAX(COALESCE(datetime_column))
+--echo #
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('10:10:10'),('10:20:30');
+SELECT MAX(a), MAX(COALESCE(a)) FROM t1;
+DROP TABLE t1;
+
 --echo #
 --echo # End of 10.1 tests
 --echo #
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 7876929a427..ea1710ecc24 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -1089,7 +1089,9 @@ bool Item_func_hybrid_result_type::get_date(MYSQL_TIME *ltime,
   case STRING_RESULT:
   {
     if (is_temporal_type(field_type()))
-      return date_op(ltime, fuzzydate);
+      return date_op(ltime,
+                     fuzzydate |
+                     (field_type() == MYSQL_TYPE_TIME ? TIME_TIME_ONLY : 0));
     char buff[40];
     String tmp(buff,sizeof(buff), &my_charset_bin),*res;
     if (!(res= str_op(&tmp)) ||