Bug #25643: SEC_TO_TIME function problem

 Checking for NULL before calling the val_xxx()
 methods only checks for such arguments that are 
 known to be NULLs at compile time. 
 The arguments that may or may not contain
 NULLs (e.g. function calls and possibly others)
 are not checked at all.
 Fixed by first calling the val_xxx() method and
 then checking for null in SEC_TO_TIME().
 In addition QUARTER() was not returning 0 (as all the 
 val_int() functions do when processing a NULL value).

mysql-test/r/func_time.result

@@ -1207,3 +1207,17 @@ SET NAMES DEFAULT;
 select str_to_date('10:00 PM', '%h:%i %p') + INTERVAL 10 MINUTE;
 str_to_date('10:00 PM', '%h:%i %p') + INTERVAL 10 MINUTE
 NULL
+CREATE TABLE t1 (a int, t1 time, t2 time, d date, PRIMARY KEY  (a));
+INSERT INTO t1 VALUES (1, '10:00:00', NULL, NULL), 
+(2, '11:00:00', '11:15:00', '1972-02-06');
+SELECT t1, t2, SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) ), QUARTER(d) 
+FROM t1;
+t1	t2	SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) )	QUARTER(d)
+10:00:00	NULL	NULL	NULL
+11:00:00	11:15:00	00:15:00	1
+SELECT t1, t2, SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) ), QUARTER(d)
+FROM t1 ORDER BY a DESC;
+t1	t2	SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) )	QUARTER(d)
+11:00:00	11:15:00	00:15:00	1
+10:00:00	NULL	NULL	NULL
+DROP TABLE t1;

mysql-test/t/func_time.test

@@ -713,3 +713,15 @@ SET NAMES DEFAULT;
 #
 
 select str_to_date('10:00 PM', '%h:%i %p') + INTERVAL 10 MINUTE;
+
+#
+# Bug #25643: SEC_TO_TIME function problem
+#
+CREATE TABLE t1 (a int, t1 time, t2 time, d date, PRIMARY KEY  (a));
+INSERT INTO t1 VALUES (1, '10:00:00', NULL, NULL), 
+       (2, '11:00:00', '11:15:00', '1972-02-06');
+SELECT t1, t2, SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) ), QUARTER(d) 
+  FROM t1;
+SELECT t1, t2, SEC_TO_TIME( TIME_TO_SEC( t2 ) - TIME_TO_SEC( t1 ) ), QUARTER(d)
+  FROM t1 ORDER BY a DESC;
+DROP TABLE t1;

sql/item_timefunc.cc

@@ -1054,7 +1054,8 @@ longlong Item_func_quarter::val_int()
 {
   DBUG_ASSERT(fixed == 1);
   TIME ltime;
-  (void) get_arg0_date(&ltime, TIME_FUZZY_DATE);
+  if (get_arg0_date(&ltime, TIME_FUZZY_DATE))
+    return 0;
   return (longlong) ((ltime.month+2)/3);
 }
 
@@ -1668,6 +1669,7 @@ String *Item_func_sec_to_time::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
   TIME ltime;
+  longlong arg_val= args[0]->val_int(); 
 
   if ((null_value=args[0]->null_value) || str->alloc(19))
   {
@@ -1675,7 +1677,7 @@ String *Item_func_sec_to_time::val_str(String *str)
     return (String*) 0;
   }
 
-  sec_to_time(args[0]->val_int(), args[0]->unsigned_flag, &ltime);
+  sec_to_time(arg_val, args[0]->unsigned_flag, &ltime);
   
   make_time((DATE_TIME_FORMAT *) 0, &ltime, str);
   return str;
@@ -1686,11 +1688,12 @@ longlong Item_func_sec_to_time::val_int()
 {
   DBUG_ASSERT(fixed == 1);
   TIME ltime;
+  longlong arg_val= args[0]->val_int(); 
   
   if ((null_value=args[0]->null_value))
     return 0;
 
-  sec_to_time(args[0]->val_int(), args[0]->unsigned_flag, &ltime);
+  sec_to_time(arg_val, args[0]->unsigned_flag, &ltime);
 
   return (ltime.neg ? -1 : 1) *
     ((ltime.hour)*10000 + ltime.minute*100 + ltime.second);