This patch (relative to 1.2.3) adds the function gdk_draw_bitmap to
gdk/gdkdraw.c.

gdk_draw_bitmap is declared in gdk.h but not defined anywhere. This
omission makes drawing bitmaps on drawables with a depth != 1 more or
less impossible.

There's a workaround involving stipples, but an actual implementation of
gdk_draw_bitmap using XCopyPlane is *much* more convenient and it
doesn't require modifying the gc.