Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > With no Win32 exception detection code in sight, I propose the following
> > patch to prevent server crashes for unusual INT_MIN integer division. 
> 
> The overflow code tries hard to avoid assuming it knows what INT_MIN and
> INT_MAX are --- this is maybe not so important for int4 but it is for
> int8 (because of our support for int8-less machines).  I don't
> immediately see how to make this test without assuming you know the
> value of INT_MIN, but we ought to try to come up with one.
> 
> We do see funny behavior on Intel chips even without Windows, so it'd
> be better to not #ifdef WIN32 but use the same overflow test for
> everyone.

> I would imagine the same problem arises with int8, has anyone checked?

Seems int8 is OK on Win32:

        postgres=# SELECT (-9223372036854775808) / (-1);
        ERROR:  bigint out of range

> Also, the overflow tests in the intNmul routines seem vulnerable.

I reproduced the crash using int4 multiplication.  Again int8
multiplication seemed OK.

I tried int2 and that seemed OK.

Updated patch attached.

-- 
  Bruce Momjian   http://candle.pha.pa.us
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +
Index: src/backend/utils/adt/int.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/int.c,v
retrieving revision 1.72
diff -c -c -r1.72 int.c
*** src/backend/utils/adt/int.c	11 Mar 2006 01:19:22 -0000	1.72
--- src/backend/utils/adt/int.c	9 Jun 2006 02:36:32 -0000
***************
*** 735,740 ****
--- 735,751 ----
  	int32		arg2 = PG_GETARG_INT32(1);
  	int32		result;
  
+ #ifdef WIN32
+ 	/*
+ 	 *	Win32 doesn't throw a catchable exception for
+ 	 *	SELECT -2147483648 /* INT_MIN */ * (-1);
+ 	 */
+ 	if (arg2 == -1 && arg1 == INT_MIN)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("integer out of range")));
+ #endif
+ 
  	result = arg1 * arg2;
  
  	/*
***************
*** 770,775 ****
--- 781,797 ----
  				(errcode(ERRCODE_DIVISION_BY_ZERO),
  				 errmsg("division by zero")));
  
+ #ifdef WIN32
+ 	/*
+ 	 *	Win32 doesn't throw a catchable exception for
+ 	 *	SELECT -2147483648 /* INT_MIN */ / (-1);
+ 	 */
+ 	if (arg2 == -1 && arg1 == INT_MIN)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("integer out of range")));
+ #endif
+ 
  	result = arg1 / arg2;
  
  	/*
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