On Mon, Nov 05, 2012 at 12:21:27PM +0000, Frank Shearar wrote:
> On 5 November 2012 11:44, David T. Lewis <lewis at mail.msen.com> wrote:
> 
> > 3) LargeNegativeIntegerTest.testMinimumNegativeIntegerArithmetic
> >
> > This is a VM capability issue (passes on VMs with the necessary update).
> > It is not something that can or should be addressed in the image, therefore
> > IMO it should not block the 4.4 release.
> 
> Ideally we'd have it an expected failure on a Cog VM and passing in
> the newer interpreter VMs, but I agree that we shouldn't delay 4.4 any
> further.

This is not a Cog issue, it is an issue that affects all VMs. It is a
real failure (not expected) and it will go away when all VMs have been
updated.  Meantime, let's just ensure that the test is green when run on
a VM (Cog or interpreter) that *does* have the necessary fix.

For background, here is the explanation in the test comment:

testMinimumNegativeIntegerArithmetic
	"We are speaking of minimum integer in underlying hardware here.
	In 2-complement, abs(INT_MIN) = (INT-MAX+1) and thus overflows hardware register.
	Since some old VM forgot this edge case they may fail and it's better to be aware of it.
	http://code.google.com/p/cog/issues/detail?id=92
	http://bugs.squeak.org/view.php?id=7705
	We only test the cases of 32 and 64 bit signed integers."

BTW, kudos to Nicolas for finding and fixing this :)

Dave