Fix for bug #27483: Casting 'scientific notation type' to 'unsigned

bigint' fails on windows.

Visual Studio does not take into account some x86 hardware limitations
which leads to incorrect results when converting large DOUBLE values
to BIGINT UNSIGNED ones.

Fixed by adding a workaround for double->ulonglong conversion on
Windows.


include/config-win.h:
  Added double2ulonglong(double) function implementing a workaround for
  broken double->ulonglong conversion on Windows/x86.
include/my_global.h:
  Define double2ulonglong() as a simple typecast for anything but
  Windows.
mysql-test/r/type_float.result:
  Added a test case for bug #27483.
mysql-test/t/type_float.test:
  Added a test case for bug #27483.

include/config-win.h

@@ -245,6 +245,15 @@ inline double ulonglong2double(ulonglong value)
 #define my_off_t2double(A) ulonglong2double(A)
 #endif /* _WIN64 */
 
+inline ulonglong double2ulonglong(double d)
+{
+  double t= d - (double) 0x8000000000000000ULL;
+
+  if (t >= 0)
+    return  ((ulonglong) t) + 0x8000000000000000ULL;
+  return (ulonglong) d;
+}
+
 #if SIZEOF_OFF_T > 4
 #define lseek(A,B,C) _lseeki64((A),(longlong) (B),(C))
 #define tell(A) _telli64(A)

include/my_global.h

@@ -713,6 +713,9 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #define ulonglong2double(A) ((double) (ulonglong) (A))
 #define my_off_t2double(A)  ((double) (my_off_t) (A))
 #endif
+#ifndef double2ulonglong
+#define double2ulonglong(A) ((ulonglong) (double) (A))
+#endif
 #endif
 
 #ifndef offsetof

mysql-test/r/type_float.result

@@ -392,4 +392,17 @@ f1 + 0e0
 1.0000000150475e+30
 -1.0000000150475e+30
 drop table t1;
+create table t1(d double, u bigint unsigned);
+insert into t1(d) values (9.2233720368547777e+18),
+(9.223372036854779e18),
+(9.22337203685479e18),
+(1.84e19);
+update t1 set u = d;
+select * from t1;
+d	u
+9.22337203685478e+18	9223372036854775808
+9.22337203685478e+18	9223372036854779904
+9.22337203685479e+18	9223372036854790144
+1.84e+19	18400000000000000000
+drop table t1;
 End of 5.0 tests

mysql-test/t/type_float.test

@@ -252,4 +252,21 @@ insert into t1 values (2e30), (-2e30);
 select f1 + 0e0 from t1;
 drop table t1;
 
+# 
+# Bug #27483: Casting 'scientific notation type' to 'unsigned bigint' fails on 
+#             windows.
+#
+
+create table t1(d double, u bigint unsigned);
+
+insert into t1(d) values (9.2233720368547777e+18),
+                         (9.223372036854779e18),
+                         (9.22337203685479e18),
+                         (1.84e19);
+
+update t1 set u = d;
+select * from t1;
+
+drop table t1;
+
 --echo End of 5.0 tests