When conserving memory in raster mode, SkiaSalBitmap may decide
to drop the pixel buffer if SkImage is created from it, since
having both wastes memory and converting between them is cheap.
But if there is still a Bitmap::ScopedReadAccess existing
for the bitmap (e.g. VclCanvasBitmap keeps it as a member),
then dropping the pixel buffer would make the data pointed to
by the read access invalid.
Technically this patch should distinguish between info and read
accesses, as info accesses do not point to pixels, but this is
simpler and hopefully doesn't make a difference in practice.
Change-Id: I307170ad4651b849feda0cf224976ca5a87e5207
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/107752
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
0e5b473a63