Specifically this patch which does not invoke _AC_PATH_X_XMKMF and
_AC_PATH_X_DIRECT internal autoconf routines when cross-compiling:
http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=33c3a47c04ab70a4dd54963fe433a171bc03747f
Without this, CFLAGS would brokenly have system include paths like
-I/usr/include/X11 when cross-compiling e.g. for windows. (And it
also resulted in annoying imake crashes for my setup...)
configure output is practically unchanged. there are still lots of
AC_TRY_COMPILE/AC_TRY_LINK replacements needed to really eliminate
the warnings, but that's for another time.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
