From patchwork Wed Oct 2 13:47:54 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: exa: only draw valid trapezoids From: Maarten Lankhorst X-Patchwork-Id: 14769 Message-Id: <524C240A.9010607@canonical.com> To: "X.Org Devel List" Date: Wed, 02 Oct 2013 15:47:54 +0200 Fixes freedesktop.org bug https://bugs.freedesktop.org/show_bug.cgi?id=67484 If t->bottom is close to MIN_INT, removing top can wraparound, so do the check properly. A similar fix should also be applied to pixman. Signed-off-by: Maarten Lankhorst --- diff --git a/exa/exa_render.c b/exa/exa_render.c index 172e2b5..807eeba 100644 --- a/exa/exa_render.c +++ b/exa/exa_render.c @@ -1141,7 +1141,8 @@ exaTrapezoids(CARD8 op, PicturePtr pSrc, PicturePtr pDst, exaPrepareAccess(pPicture->pDrawable, EXA_PREPARE_DEST); for (; ntrap; ntrap--, traps++) - (*ps->RasterizeTrapezoid) (pPicture, traps, -bounds.x1, -bounds.y1); + if (xTrapezoidValid(traps)) + (*ps->RasterizeTrapezoid) (pPicture, traps, -bounds.x1, -bounds.y1); exaFinishAccess(pPicture->pDrawable, EXA_PREPARE_DEST); xRel = bounds.x1 + xSrc - xDst; diff --git a/render/picture.h b/render/picture.h index c85353a..fcd6401 100644 --- a/render/picture.h +++ b/render/picture.h @@ -211,7 +211,7 @@ typedef pixman_fixed_t xFixed; /* whether 't' is a well defined not obviously empty trapezoid */ #define xTrapezoidValid(t) ((t)->left.p1.y != (t)->left.p2.y && \ (t)->right.p1.y != (t)->right.p2.y && \ - (int) ((t)->bottom - (t)->top) > 0) + ((t)->bottom > (t)->top)) /* * Standard NTSC luminance conversions: