XCopyArea copies blank from second monitor.
Also, seems that Xdamage doesn't produce messages for changes on second monitor.
As result, correctly working in single-screen setups applications fail to work on xinerama setups.
F.e., vino ( http://bugzilla.gnome.org/show_bug.cgi?id=346258 ) shows completely blank second screen, and if disable XCoypArea, it shows no changes on second screen (seems, with no Xdamage information on it).
as i see in code, difference is XCopyArea uses (*pGC->ops->CopyArea), while XGetSubImage uses (*pDraw->pScreen->GetImage)
so, problem in CopyArea, and have no problem in GetImage
This is a two-part bug, but the damage half of it affects composite managers on X servers that recently re-allowed Xinerama and Composite at the same time.
Assigning. Fix for the Damage extension is out for review: http://lists.x.org/archives/xorg-devel/2011-September/025701.html
Adding to the 1.11 tracker.
Since this is on the 1.11 tracker, I should probably post a status update. My change sent to the list was never reviewed, but I think it also probably doesn't work for damage listeners attached to windows, which my short-sighted test app doesn't catch. I'll need to fix up the test app and extend the patch before sending it out for re-review. The current change should be enough to fix Vino, since I think it only watches for damage on the root, so I'll leave it up to Jeremy whether to take the current patch as-is or wait for my limited free time in my schedule to allow me to fix it.
As for the XCopyArea part of this bug, I think that's a duplicate of bug 25113.
Yeah, I'd rather wait for a complete fix. Do you have an ETA?
The Damage half of this should be fixed in 1.15 and later by:
Author: Adam Jackson <email@example.com>
Date: Mon Sep 16 15:17:26 2013 -0400
damageext: Xineramify (v7)
What's the CopyArea part of the problem? PanoramiXCopyArea definitely includes code to handle MIT-SHM pixmaps already, I don't see anything obviously wrong with it.