Re: [bug-libunistring] case folding output size?

[Aleksander Morgado]

> > What if the resultbuf passed doesn't have enough space for the
> > case-folded and normalized string?
> 
> This is documented at the end of the doc section "Conventions":
>   <http://www.gnu.org/software/libunistring/manual/html_node/Conventions.html>
>   "Functions returning a string result take a (resultbuf, lengthp)
>    argument pair. If resultbuf is not NULL and the result fits into *lengthp
>    units, it is put in resultbuf, and resultbuf is returned. Otherwise, a
>    freshly allocated string is returned. In both cases, *lengthp is set to
>    the length (number of units) of the returned string. In case of error,
>    NULL is returned and errno is set."

Oops, missed that part, understood now.

> 
> > And, if NFC normalization desired in the output, would it be safe to say
> > that the output length will be less or equal than the input length?
> 
> No, it is not. The file tests/test-u8-casefold.c has a couple of examples that
> show a case-folded string can be longer than the original string.
> 
> In summary, these Unicode aware string manipulations have so complex details
> that the classical assumptions all fail.
> 

I wasn't aware of those case-fold situations, so thanks!

-- 
Aleksander