Re: What's the right way to detect libxml2?

[Andy Moreton <andrewjmoreton@gmail.com>]

On Tue 24 Oct 2017, Robert Pluim wrote:

> Andy Moreton <andrewjmoreton@gmail.com> writes:
>
>> On Tue 24 Oct 2017, Clément Pit-Claudel wrote:
>>
>>> On 2017-10-24 09:38, Andy Moreton wrote:
>>>> For libxml2, try using (shr-render-buffer) on an HTML/XML buffer to get
>>>> the library loaded.
>>>
>>> Is that better than just calling libxml-parse-xml-region and checking for a
>>> nil return value? It sounds like shr-render-buffer would do a lot more — do we
>>> need that?
>>
>> No, it was just an example of doing something to force the library to be
>> loaded. Your version is simpler, and having (libxml-available-p) would
>> be even better.
>>
>>     AndyM
>
> Like thus? Very lightly tested on GNU/Linux only. Might need a NEWS
> entry.
>
Works for me on a 64bit MinGW64/MSYS2 build of emacs-26 on Windows 10.

I don't think you need to remove the HAVE_LIBXML2 conditionals, as lisp
code can check (fboundp 'libxml-available-p) before calling it, and it
may break builds without libxml2 support.

Also, the libxml-available-p doc string claims it returns a list of
capabilities (which is true for gnutls-available-p), but it only returns
nil or t.

Thanks for working on this,

    AndyM