Bug#15098 CAST(column double TO signed int), wrong result

field.cc:
  Adding longlong range checking to return
  LONGLONG_MIN or LONGLONG_MAX when out of range. 
  Using (longlong) cast only when range is ok.
cast.test:
  Adding test case.
cast.result:
  Fixing results accordingly.

mysql-test/r/cast.result

@@ -267,3 +267,11 @@ Warning	1105	Cast to signed converted positive out-of-range integer to it's nega
 select cast(1.0e+300 as signed int);
 cast(1.0e+300 as signed int)
 9223372036854775807
+CREATE TABLE t1 (f1 double);
+INSERT INTO t1 SET f1 = -1.0e+30 ;
+INSERT INTO t1 SET f1 = +1.0e+30 ;
+SELECT f1 AS double_val, CAST(f1 AS SIGNED INT) AS cast_val FROM t1;
+double_val	cast_val
+-1e+30	-9223372036854775808
+1e+30	9223372036854775807
+DROP TABLE t1;

mysql-test/t/cast.test

@@ -152,4 +152,13 @@ select cast(repeat('1',20) as signed);
 #
 select cast(1.0e+300 as signed int);
 
+#
+# Bugs: #15098: CAST(column double TO signed int), wrong result
+#
+CREATE TABLE t1 (f1 double);
+INSERT INTO t1 SET f1 = -1.0e+30 ;
+INSERT INTO t1 SET f1 = +1.0e+30 ;
+SELECT f1 AS double_val, CAST(f1 AS SIGNED INT) AS cast_val FROM t1;
+DROP TABLE t1;					   
+
 # End of 4.1 tests

sql/field.cc

@@ -3385,6 +3385,11 @@ longlong Field_double::val_int(void)
   else
 #endif
     doubleget(j,ptr);
+  /* Check whether we fit into longlong range */
+  if (j <= (double) LONGLONG_MIN)
+    return (longlong) LONGLONG_MIN;
+  if (j >= (double) (ulonglong) LONGLONG_MAX)
+    return (longlong) LONGLONG_MAX;
   return ((longlong) j);
 }