avoid skia assert and slow-path

Otherwise, several lines below, we might call
mpAlphaVDev->GetBitmap
which will return no bitmap (because the resulting bitmap would be
empty).
And then either we will hit the assert a few lines lower, or we will go
into the very very slow path below.

Change-Id: I41a62cddef5e0a6822ca09ed954e3fe431ca0021
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/154097
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

0 files changed, 0 insertions, 0 deletions