During screen attach/detach, we may end up in a situation where the
window has a 0x0 size, and we end up painting to the window, in which
case we were trying to create an IOSurface of size 0x0. This resulted
in the creation failing, triggering an assert.
We now guard the surface creation with a check for the backing store
size being non-empty, and for empty sizes we fall back to a plain
null-QImage for our paint device.
Fixes: QTBUG-128731
Pick-to: 6.5 6.2
Invaluable-research-by: Viktor Arvidsson
Change-Id: I06ea582c87fb0d359387ef9495451801612701c9
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 58caa18d2ff1a67e16f960f5bd6b804cdaec4063)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
11c8b80f4b