On Sun, Jan 03, 2021 at 08:48:20PM +0100, Bruno Haible wrote: > > iconv.m4 clears HAVE_ICONV if it detects iconv() bugs. Docs list those bugs > > under "Portability problems fixed by Gnulib:". If changing HAVE_ICONV were > > enough to qualify as a fix, then "This function is missing on some > > platforms" > > would also belong under that heading. I'm proposing to move those bugs > > under > > "not fixed by Gnulib". > > Good point. Yes, it doesn't belong under "fixed by Gnulib". But "not fixed by > Gnulib" is also not the right category. I'll list these under "handled by > Gnulib", with an extra explanation.
I like having the separate section. Since you're doing that, "This function is missing on some platforms:" also belongs under "handled by", not under "not fixed". > > Two of those iconv() bugs involve what POSIX calls "non-identical > > conversion". > > (GNU libc calls it "non-reversible conversion".) The gnulib docs and code > > comments use terms "failures" and "conversion errors", but these bugs don't > > entail the distinct POSIX concept of "error" or failure. Hence, I propose > > standardizing on the term "non-identical conversion". > > "non-identical conversion" is a nonsensical term. Therefore it's better not > to use it. (Two objects can be identical if they are in the same mathematical > set. But when we use iconv, we are doing a mapping between the minimal byte > sequences of the input character set and the minimal byte sequences of the > destination character set; these are two different sets. If anyone uses > the term "identical" here, it would mean that the sets have an intersection, > and that the corresponding byte sequences are the same (e.g. like ISO-8859-1 > and UTF-8 have, as intersection, the set of 1-byte sequences with values >= 0, > <= 0x7F).) If https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html used "identical" to mean "same byte sequence", it would be requiring an ISO-8859-1 => UTF-8 conversion to increment the iconv() return value upon converting 0xA1 to 0xC2 0xA1. Most implementations don't do that. (HP-UX does, and Gnulib calls it a bug.) https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html also defines what it means to "fail" or experience an "error", and it classifies "non-identical conversion" as neither of those things. Using a term unattested in POSIX, like "non-reversible conversion", would solve that problem. > --- a/modules/iconv-h > +++ b/modules/iconv-h > @@ -46,7 +46,9 @@ endif > MOSTLYCLEANFILES += iconv.h iconv.h-t > > Include: > -<iconv.h> > +#if HAVE_ICONV_H > +# include <iconv.h> > +#endif Doesn't this module cause the header to exist?
