Comment 38 for bug 1216252

(In reply to comment #33)
> No, that's not it, sorry. I can still reproduce it with "SNA compiled from
> 2.21.14-27-g9645e71".
>
> I'll retest with latest drm-nightly-intel

Can you also try with the quick little hack from c31

diff --git a/src/sna/sna_composite.c b/src/sna/sna_composite.c
index 58dd356..6f24eeb 100644
--- a/src/sna/sna_composite.c
+++ b/src/sna/sna_composite.c
@@ -520,7 +520,7 @@ sna_composite_fb(CARD8 op,
        if (mask)
                validate_source(mask);

- if (mask == NULL &&
+ if (mask == NULL && 0 &&
            src->pDrawable &&
            dst->pDrawable->bitsPerPixel >= 8 &&
            src->filter != PictFilterConvolution &&

to sanity check that I am barking up the right tree.