Backing Store not working in 8 Bit color depth with vesa driver

Patrick O'Donnell pao at
Mon Sep 19 11:03:09 PDT 2011

>Date: Mon, 19 Sep 2011 10:20:12 -0500
>From: Doug Kuvaas <doug.kuvaas at>
>I posted to this list earlier about not getting color in 8 bit depth
>using the intel driver.  After some assistance I was able to get 8 bit
>color to show in color.  However, now the backing store does not seem
>to work, so the application I am attempting to run leaves blank areas
>on the display whenever a menu or other window covers that area.
>xdpyinfo does report that the backing store is on.

We, too, ran afoul of this change.  I turns out, though, that X
clients were never allowed to presume the server would provide backing
store (or save unders).  Even if the server announced that it
supported backing store, it was allowed, if resources became tight, to
refuse to provide it for any window that asked.

It sounds like the client you're attempting to run is presuming upon
the backing store and is ignoring the expose events that are being
generated.  This, unfortunately, is broken behavior.

		- Patrick

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