commit 6c559b122add7db32b06faa15854df58b30460f6
author Luboš Luňák <l.lunak@collabora.com> Mon Apr 20 17:35:30 2020 +0200
committer Luboš Luňák <l.lunak@collabora.com> Tue Apr 21 10:02:48 2020 +0200
tree 6dc74cb544b57fa78d9a4e62a9e0a2665e158db9
parent 9b7a2d33e9dcb5e4131e4901969d5853efdaf6e8

work around copy-to-self SkSurface::draw() being buggy (tdf#132051)

This may become the actual fix or may be removed later depending
on the outcome of
https://groups.google.com/d/msgid/skia-discuss/202004151937.05051.l.lunak%40collabora.com .

Change-Id: I709f3e7bffbe86ddb2f6d75724bf30e4b0f0116e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/92587
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

vcl/skia/gdiimpl.cxx

diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index 1937115..6926823 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -897,6 +897,16 @@
    // Using SkSurface::draw() should be more efficient than SkSurface::makeImageSnapshot(),
    // because it may detect copying to itself and avoid some needless copies.
    // It cannot do a subrectangle though, so clip.
    if (canvas == surface->getCanvas())
    {
        // TODO: Currently copy-to-self is buggy with SkSurface::draw().
        SkPaint paint;
        paint.setBlendMode(SkBlendMode::kSrc); // copy as is, including alpha
        canvas->drawImageRect(surface->makeImageSnapshot(),
                              SkIRect::MakeXYWH(nSrcX, nSrcY, nSrcWidth, nSrcHeight),
                              SkRect::MakeXYWH(nDestX, nDestY, nSrcWidth, nSrcHeight), &paint);
        return;
    }
    canvas->save();
    canvas->clipRect(SkRect::MakeXYWH(nDestX, nDestY, nSrcWidth, nSrcHeight));
    SkPaint paint;