Bug#52159 returning time type from function and empty left join causes debug assertion

Problem: Item_copy did not set "fixed", which resulted in DBUG_ASSERT in some cases.
Fix: adding  initialization of the "fixed" member

Adding tests:
  mysql-test/include/ctype_numconv.inc
  mysql-test/r/ctype_binary.result
  mysql-test/r/ctype_cp1251.result
  mysql-test/r/ctype_latin1.result
  mysql-test/r/ctype_ucs.result

Adding initialization of the "fixed" member:
  sql/item.h

mysql-test/include/ctype_numconv.inc

@@ -1606,3 +1606,22 @@ drop function f1;
 --echo # End of WL#2649 Number-to-string conversions
 --echo #
 
+--echo #
+--echo # Bug#52159 returning time type from function and empty left join causes debug assertion
+--echo #
+CREATE FUNCTION f1() RETURNS TIME RETURN 1;
+CREATE TABLE t1 (b INT);
+INSERT INTO t1 VALUES (0);
+SELECT f1() FROM t1 LEFT JOIN (SELECT 1 AS a FROM t1 LIMIT 0) AS d ON 1 GROUP BY a;
+DROP FUNCTION f1;
+DROP TABLE t1;
+
+SET NAMES latin1;
+SET sql_mode='';
+CREATE TABLE t1(a char(215) CHARACTER SET utf8 NOT NULL DEFAULT '', KEY(a));
+INSERT INTO t1 VALUES ();
+--disable_warnings
+SELECT maketime(`a`,`a`,`a`) FROM t1 GROUP BY 1;
+--enable_warnings
+DROP TABLE t1;
+SET sql_mode=default;

mysql-test/r/ctype_binary.result

@@ -2567,5 +2567,25 @@ drop function f1;
 # End of WL#2649 Number-to-string conversions
 #
 #
+# Bug#52159 returning time type from function and empty left join causes debug assertion
+#
+CREATE FUNCTION f1() RETURNS TIME RETURN 1;
+CREATE TABLE t1 (b INT);
+INSERT INTO t1 VALUES (0);
+SELECT f1() FROM t1 LEFT JOIN (SELECT 1 AS a FROM t1 LIMIT 0) AS d ON 1 GROUP BY a;
+f1()
+00:00:01
+DROP FUNCTION f1;
+DROP TABLE t1;
+SET NAMES latin1;
+SET sql_mode='';
+CREATE TABLE t1(a char(215) CHARACTER SET utf8 NOT NULL DEFAULT '', KEY(a));
+INSERT INTO t1 VALUES ();
+SELECT maketime(`a`,`a`,`a`) FROM t1 GROUP BY 1;
+maketime(`a`,`a`,`a`)
+00:00:00
+DROP TABLE t1;
+SET sql_mode=default;
+#
 # End of 5.5 tests
 #

mysql-test/r/ctype_cp1251.result

@@ -2649,5 +2649,25 @@ drop function f1;
 # End of WL#2649 Number-to-string conversions
 #
 #
+# Bug#52159 returning time type from function and empty left join causes debug assertion
+#
+CREATE FUNCTION f1() RETURNS TIME RETURN 1;
+CREATE TABLE t1 (b INT);
+INSERT INTO t1 VALUES (0);
+SELECT f1() FROM t1 LEFT JOIN (SELECT 1 AS a FROM t1 LIMIT 0) AS d ON 1 GROUP BY a;
+f1()
+00:00:01
+DROP FUNCTION f1;
+DROP TABLE t1;
+SET NAMES latin1;
+SET sql_mode='';
+CREATE TABLE t1(a char(215) CHARACTER SET utf8 NOT NULL DEFAULT '', KEY(a));
+INSERT INTO t1 VALUES ();
+SELECT maketime(`a`,`a`,`a`) FROM t1 GROUP BY 1;
+maketime(`a`,`a`,`a`)
+00:00:00
+DROP TABLE t1;
+SET sql_mode=default;
+#
 # End of 5.5 tests
 #

mysql-test/r/ctype_latin1.result

@@ -2977,5 +2977,25 @@ drop function f1;
 # End of WL#2649 Number-to-string conversions
 #
 #
+# Bug#52159 returning time type from function and empty left join causes debug assertion
+#
+CREATE FUNCTION f1() RETURNS TIME RETURN 1;
+CREATE TABLE t1 (b INT);
+INSERT INTO t1 VALUES (0);
+SELECT f1() FROM t1 LEFT JOIN (SELECT 1 AS a FROM t1 LIMIT 0) AS d ON 1 GROUP BY a;
+f1()
+00:00:01
+DROP FUNCTION f1;
+DROP TABLE t1;
+SET NAMES latin1;
+SET sql_mode='';
+CREATE TABLE t1(a char(215) CHARACTER SET utf8 NOT NULL DEFAULT '', KEY(a));
+INSERT INTO t1 VALUES ();
+SELECT maketime(`a`,`a`,`a`) FROM t1 GROUP BY 1;
+maketime(`a`,`a`,`a`)
+00:00:00
+DROP TABLE t1;
+SET sql_mode=default;
+#
 # End of 5.5 tests
 #

mysql-test/r/ctype_ucs.result

@@ -3808,6 +3808,26 @@ drop function f1;
 #
 # End of WL#2649 Number-to-string conversions
 #
+#
+# Bug#52159 returning time type from function and empty left join causes debug assertion
+#
+CREATE FUNCTION f1() RETURNS TIME RETURN 1;
+CREATE TABLE t1 (b INT);
+INSERT INTO t1 VALUES (0);
+SELECT f1() FROM t1 LEFT JOIN (SELECT 1 AS a FROM t1 LIMIT 0) AS d ON 1 GROUP BY a;
+f1()
+00:00:01
+DROP FUNCTION f1;
+DROP TABLE t1;
+SET NAMES latin1;
+SET sql_mode='';
+CREATE TABLE t1(a char(215) CHARACTER SET utf8 NOT NULL DEFAULT '', KEY(a));
+INSERT INTO t1 VALUES ();
+SELECT maketime(`a`,`a`,`a`) FROM t1 GROUP BY 1;
+maketime(`a`,`a`,`a`)
+00:00:00
+DROP TABLE t1;
+SET sql_mode=default;
 SET NAMES latin1;
 #
 # End of 5.5 tests

sql/item.h

@@ -2791,6 +2791,7 @@ protected:
     cached_field_type= item->field_type();
     cached_result_type= item->result_type();
     unsigned_flag= item->unsigned_flag;
+    fixed= item->fixed;
   }
 
 public: