GNOME Bugzilla – Bug 613668
Enable -Wundef
Last modified: 2012-06-16 11:37:00 UTC
The only headers that had this ( http://cgit.freedesktop.org/gstreamer/gst-plugins-bad/commit/?id=1cd74f1e4045e991d4c14125c989999a0e1af226 ) problem so far are 2 files from Windows PSDK which have to be copied from said SDK manually anyway (because the whole SDK doesn't work well with GCC/MinGW), so there is no reason not to fix them (which i did). And that only due to lack of some declarations in MinGW headers (which can and will be fixed someday).
As said on IRC, I'm very careful to not trigger warnings from bad headers. Warning flags should make the lives of people easier, not harder. So until the headers is fixed upstream (read: by mingw) I guess it's best to leave that warning disabled, so other people that try to compile for Windows don't need to fix their headers. And -Wundef is not very important, it's just nice to have.
WONTFIXing as per comment #1.