[comp.windows.x] Nonsensical backing store set in converter

net@TUB.BITNET (Oliver Laumann) (12/16/88)

The string-to-backing-store converter in the Xmu library returns a
backing store of Always+WhenMapped+NotUseful when it is invoked
with the string "default".  The Xlib documentation nowhere states
that this is a valid value for the backing store attribute.

Am I missing something?

Regards,
--
Oliver Laumann              net@TUB.BITNET              net@tub.UUCP

keith@EXPO.LCS.MIT.EDU (Keith Packard) (12/16/88)

> The string-to-backing-store converter in the Xmu library returns a
> backing store of Always+WhenMapped+NotUseful when it is invoked
> with the string "default".  The Xlib documentation nowhere states
> that this is a valid value for the backing store attribute.

This is my fault.  I wanted a way of indicating that the
backing store attribute in the window not be specified in
the SetWindowAttributes; the R3 servers have a hack option
(-wm) which turns WhenMapped backing store on all windows
which don't specify an explicit value.

Obviously your code will need to recognise the magic value and
handle it specially.  Good thing there isn't any specification
for the Xmu library.

						Keith Packard
						MIT X Consortium
						(617) 253-1428
						keith@EXPO.LCS.MIT.EDU