On Oct 30 10:07, Ken Brown wrote: > Hi Corinna, > > On 10/30/2015 8:03 AM, Corinna Vinschen wrote: > >On Oct 29 18:21, Ken Brown wrote: > >>The fallback I had in mind is to return the shorter string if they have > >>different lengths and otherwise to revert to wcscmp. > > > >I had a longer look into this suggestion and the below code and it took > >me some time to find out what bugged me with it: > > > >What about str/wcsxfrm? > > > >Per POSIX, calling strcmp on the result of strxfrm is equivalent to > >calling strcoll (analogue with wcs*). If you extend *coll to perform an > >extra check on the length, you will have cases in which the above rule > >fails. You can't perform the length test on the result of *xfrm and > >expect the same result as in *coll. > > > >In fact, when calling LCMapStringW with NORM_IGNORESYMBOLS (you would > >have to do this anyway if we add this flag in *coll), the resulting > >transformed strings created from the input strings "11" and "1.1" would > >be identical, so a length test on the xfrm string is not meaningful at > >all. > > > >The bottom line is, afaics, we must make sure that CompareStringW and > >LCMapStringW are called the same way, and their result/output has to be > >returned to the caller. Performing an extra check in *coll which can't > >be reliably performed in *xfrm is not feasible. > > > >Does that make sense? > > Yes, I see the problem, and I don't see a good way around it. So I think we > probably have to leave things as they are and live with the fact that we > can't do comparisons that ignore whitespace and punctuation. > > The alternative of allowing str/wcscoll to return 0 on unequal strings > doesn't seem feasible in view of Eric's comments. > > What about the other issue I raised: Should setlocale return null to > indicate an error if it's given an invalid locale name like en_DE.UTF-8? Huh. Interesting. You're runing Windows10, right? After some digging it turns out there's a bug in W10. LocaleNameToLCID() does *not* fail and return with an error if it doesn't know a locale. That would be too simple I guess. Rather, it returns a value LOCALE_CUSTOM_UNSPECIFIED, 0x1000. So all unknown locales are now treated as custom locale. Duh! I fear the answer when trying to report this. Probably it's a feature... I applied a patch to workaround this feature. Thanks for the testcase, btw :) Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat