Xdarwin often uses alloca() for temporary storage. Apparently on Darwin
an alloca() request of 519872 bytes or more seg faults. In the Netscape
case, Select All creates a complex clipping region, and a ~1 MB alloca()
is needed to process the drawing.
This patch to xc/config/cf/darwin.cf disables alloca(), using xalloc (aka
malloc) for temporary storage instead. I've posted to darwin-development
asking about alloca, so if it is a Darwin bug and gets fixed later we can
go back to using it.
(This is against the masterless version; the important part is the
addition of -DNO_ALLOCA to the StandardDefines.)