Building the man pages via xsltproc requires "docbook.xsl"
which is part of docbook.
Previously, we would build the man pages solely based on
"--enable-introspection", which checks for the presence of
xsltproc, but not docbook. This can lead to build failure
when docbook is not available, but "--enable-introspection"
is given.
Instead of adding yet another configure option to fine-tune
and say "--with-docbook --disable-gtk-doc", just simplify it.
Now, documentation (both man pages and setting docs) will be generated
with "--enable-gtk-doc" and "--enable-introspection".
If the documentation is not about to be generated, pre-generated docs
will be installed if they are available. That is commonly the case
with a source tarball, but not with a git checkout.
Finally, if documentation is nither generated nor pre-generated,
no documentation will be installed *duh*.
This removes the possibility to treat man pages separate from settings
docs. Now you either generate both, install both pre-generated, or don't
get any of them.
https://bugzilla.gnome.org/show_bug.cgi?id=778551
b599f1b743