Re: Collation tests in fns-tests.el

[Ken Brown <kbrown@cornell.edu>]

On 10/30/2015 5:35 PM, Eli Zaretskii wrote:
>> Cc: michael.albinus@gmx.de, emacs-devel@gnu.org
>> From: Ken Brown <kbrown@cornell.edu>
>> Date: Fri, 30 Oct 2015 17:10:48 -0400
>>
>> On 10/30/2015 4:28 PM, Eli Zaretskii wrote:
>>> You already said in that discussion what I'd suggest ;-)
>>>
>>> Since Cygwin tries to be compatible to GNU/Linux (i.e. glibc), it
>>> should indeed use some non-zero flags in its implementation of string
>>> collation-dependent comparison.  IMO, it makes no sense not to do
>>> that, since users expect that to happen.
>>
>> Yes, I agree completely.  The issue is implementation.  Simply using the
>> NORM_IGNORESYMBOLS flag yields comparison functions that can return 0 on
>> unequal strings.  Eric pointed out the problem with that; moreover, it
>> seriously violates users' expectations and compatibility with glibc.  I
>> thought I had a way around that, but Corinna pointed out in
>> https://www.cygwin.com/ml/cygwin/2015-10/msg00559.html why my suggestion
>> doesn't work.  At this point I'm out of ideas.
>
> I don't see why that conclusion is the only reasonable one (the
> "seriously violates users' expectation" part surprises me), but I
> don't really consider myself an expert on this, certainly not in
> Cygwin.
>
> If Cygwin's implementation of strcoll cannot be fixed, then we should
> treat this test on Cygwin as expected failure.

I'll probably do that, but I'll wait to see if Michael has anything to add.

Ken