meson: X11 dependency is automagic
Submitted by Quentin Glidic
In commit f38e3e2c, the X11 dependency was made optional… in the check function. If you do not want to build the X11 helper library, you can simply use -Dx11=false. Having this change (f38e3e2c) was wrong, introducing an automagic dependency. If for some reason, the libX11 package is faulty, the gdk-pixbuf build will simply ignore the -Dx11=true that the package manager added to build it, resulting in a wrong gdk-pixbuf package state, making other packages fail while gdk-pixbuf should have refused to build altogether.
There are three possible solutions: simply tell Windows people to pass -Dx11=false, use a true/false/auto scheme for the option (default to "auto", "true" forces the dep, "false" force-disable the library) or have a Windows-specific test along with get_option('x11').