[tlbuild] Missing includes for zlib when building woff2 (dvisvgm)

[Mojca Miklavec]

Dear Martin,

On Mon, 25 Mar 2019 at 19:36, Martin Gieseking wrote:
>
> > However this fails when building dvisvgm's built-in dependency woff2.
> > When configuring dvisvgm itself the zlib is found and the flags seem
> > to be there, but they don't seem to propagate all the way down to
> > woff2.
>
> I'm not sure if I understand the problem correctly. Does woff2 require
> zlib in your build environment? That would be strange because woff2 uses
> the brotli compression library and doesn't rely on zlib. Actually, I
> can't find any reference to zlib in the subset of the woff2 sources
> bundled with dvisvgm. Could you send me a build log with the
> corresponding error messages?

I'm sorry, I slightly messed it up (also when investigating the
sources), it's ff-woff, not woff2.

This is the error message, clearly missing the include directory where
zlib is present:

x86_64-w64-mingw32-gcc -DHAVE_CONFIG_H -I.
-I../../../../../../texk/dvisvgm/dvisvgm-src/libs/ff-woff -I../../..
 -I../../../../../../texk/dvisvgm/dvisvgm-src/libs/ff-woff/inc
-I../../../../../../texk/dvisvgm/dvisvgm-src/libs/ff-woff/fontforge -g
-O2 -MT fontforge/woff.o -MD -MP -MF $depbase.Tpo -c -o
fontforge/woff.o
../../../../../../texk/dvisvgm/dvisvgm-src/libs/ff-woff/fontforge/woff.c
&&\
mv -f $depbase.Tpo $depbase.Po
../../../../../../texk/dvisvgm/dvisvgm-src/libs/ff-woff/fontforge/woff.c:36:11:
fatal error: zlib.h: No such file or directory
 # include <zlib.h>
           ^~~~~~~~
compilation terminated.

The file dvisvgm-src/libs/ff-woff/Makefile actually contains the
correct definition of ZLIB_INCLUDES, but it's not used anywhere. It's
only used inside of
    dvisvgm-src/src/Makefile:AM_CFLAGS = $(WARNING_CFLAGS)
$(ZLIB_INCLUDES) $(CODE_COVERAGE_CFLAGS) \
just not in any of the libs.

I can try to zip the full tree and send it off-list if the information
above is not sufficient.

Thank you,
    Mojca