bug#25967: [PATCH] Add support for ImageMagick 7 (Bug#25967)

[Karl Otness]

I hate to say this, but it looks like the modified patch might not be
linking up quite right. It seems like the issue has to do with the new
"IMAGEMAGICK7" prefix for EMACS_CHECK_MODULES. Some of the downstream
tests, specifically looking for MagickRelinquishMemory try to use the
IMAGEMAGICK_CFLAGS which won't be defined if configure finds version
7. The test will then fail ImageMagick and it won't be linked.

I don't remember exactly, but I think this may have been the reason
why I had initially set it up to use the same HAVE_IMAGEMAGICK prefix
for both pkg-config checks, and then manually added the
IMAGEMAGICK_MAJOR definition to sort out which was actually found.

Using separate test variables can probably work, but will require
updating the AC_CHECK_FUNCS tests later on. When I put together the
initial patch, I think I wanted to touch as little of configure as
possible, so I left those alone.

It may be simpler to go back to using the same IMAGEMAGICK prefix for
both package checks, but I agree it is nicer to not re-use the same
pkg-config variables.

Thanks for helping get this checked in.

Karl
On Mon, Aug 27, 2018 at 9:10 PM Glenn Morris <rgm@gnu.org> wrote:
>
> Karl Otness wrote:
>
> > I have attached a patch which adds support for ImageMagick version 7.
>
> Thanks very much! It looks much simpler than I was expecting.
>
> I applied it as 5729486, then tweaked it in bf1b147 (mainly to avoid
> printing two identical "checking for imagemagick"); it would be good if you
> check I did not break it. :)
>
> We normally like to get copyright assignments for Emacs; see eg
> https://www.gnu.org/licenses/why-assign.en.html
>
> I think your patch is just small enought not to require this.
> But if you would like to contribute more in future, or just would like
> to, you can start the assignment process by filing out the form at
>
> http://git.savannah.gnu.org/cgit/gnulib.git/tree/doc/Copyright/request-assign.future
>
> Thanks again!