Fix for bug #8935 CAST(time AS DECIMAL) crashes

mysql-test/r/cast.result:
  test result
mysql-test/r/func_group.result:
  test result
mysql-test/t/cast.test:
  test case
sql/field.cc:
  this assert isn't correct actually

mysql-test/r/cast.result

@@ -203,3 +203,9 @@ cast(@v1 as decimal(22, 2))
 select cast(-1e18 as decimal(22,2));
 cast(-1e18 as decimal(22,2))
 -1000000000000000000.00
+create table t1(s1 time);
+insert into t1 values ('11:11:11');
+select cast(s1 as decimal(7,2)) from t1;
+cast(s1 as decimal(7,2))
+111111.00
+drop table t1;

mysql-test/r/func_group.result

@@ -855,7 +855,6 @@ select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
 col1	sum(col1)	max(col1)	min(col1)
 5.000000000010	10.000000000020	5.000000000010	5.000000000010
 DROP TABLE t1;
-
 CREATE TABLE t1(
 id int PRIMARY KEY,
 a  int,

mysql-test/t/cast.test

@@ -126,3 +126,8 @@ select cast(cast('1.2' as decimal(3,2)) as signed);
 set @v1=1e18;
 select cast(@v1 as decimal(22, 2));
 select cast(-1e18 as decimal(22,2));
+
+create table t1(s1 time);
+insert into t1 values ('11:11:11');
+select cast(s1 as decimal(7,2)) from t1;
+drop table t1;

sql/field.cc

@@ -626,7 +626,6 @@ int Field_str::store_decimal(const my_decimal *d)
 
 my_decimal *Field_str::val_decimal(my_decimal *decimal_value)
 {
-  DBUG_ASSERT(result_type() == INT_RESULT);
   longlong nr= val_int();
   int2my_decimal(E_DEC_FATAL_ERROR, nr, 0, decimal_value);
   return decimal_value;