uxa: Fallback to pixman if source is out-of-bounds

If the source is outside the drawable, then CopyArea will fail to
initialise the source correctly. The simplest fix in this case is to
fallback to pixman to generate the source texture.

Fixes:

  Bug 28497 - Graphics corruption after opening a specific website
  https://bugs.freedesktop.org/show_bug.cgi?id=28497

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit b58a6a39c1568800938eb0e3ebc7664683b61200)

Signed-off-by: Owain G. Ainsworth <oga@openbsd.org>

1 files changed, 28 insertions, 27 deletions

diff --git a/uxa/uxa-render.c b/uxa/uxa-render.c
index ed380e91..056b60a4 100644
--- a/uxa/uxa-render.c
+++ b/uxa/uxa-render.c
@@ -720,6 +720,21 @@ uxa_render_picture(ScreenPtr screen,
 	return picture;
 }
 
+static int
+drawable_contains (DrawablePtr drawable, int x, int y, int w, int h)
+{
+	if (x < 0 || y < 0)
+		return FALSE;
+
+	if (x + w > drawable->width)
+		return FALSE;
+
+	if (y + h > drawable->height)
+		return FALSE;
+
+	return TRUE;
+}
+
 PicturePtr
 uxa_acquire_drawable(ScreenPtr pScreen,
 		     PicturePtr pSrc,
@@ -729,14 +744,15 @@ uxa_acquire_drawable(ScreenPtr pScreen,
 {
 	PixmapPtr pPixmap;
 	PicturePtr pDst;
-	GCPtr pGC;
 	int depth, error;
 	int tx, ty;
+	GCPtr pGC;
 
 	depth = pSrc->pDrawable->depth;
-	if (depth == 1 ||
-	    pSrc->filter == PictFilterConvolution || /* XXX */
-	    !transform_is_integer_translation(pSrc->transform, &tx, &ty)) {
+	if (!transform_is_integer_translation(pSrc->transform, &tx, &ty) ||
+	    !drawable_contains(pSrc->pDrawable, x + tx, y + ty, width, height) ||
+	    depth == 1 ||
+	    pSrc->filter == PictFilterConvolution) {
 		/* XXX extract the sample extents and do the transformation on the GPU */
 		pDst = uxa_render_picture(pScreen, pSrc,
 					  pSrc->format | (BitsPerPixel(pSrc->pDrawable->depth) << 24),
@@ -744,7 +760,7 @@ uxa_acquire_drawable(ScreenPtr pScreen,
 
 		goto done;
 	} else {
-		if (width == pSrc->pDrawable->width && height == pSrc->pDrawable->depth) {
+		if (width == pSrc->pDrawable->width && height == pSrc->pDrawable->height) {
 			*out_x = x + pSrc->pDrawable->x;
 			*out_y = y + pSrc->pDrawable->y;
 			return pSrc;
@@ -758,7 +774,7 @@ uxa_acquire_drawable(ScreenPtr pScreen,
 		return 0;
 
 	/* Skip the copy if the result remains in memory and not a bo */
-	if (!uxa_drawable_is_offscreen(&pPixmap->drawable)) {
+	if (!uxa_pixmap_is_offscreen(pPixmap)) {
 		pScreen->DestroyPixmap(pPixmap);
 		return 0;
 	}
@@ -775,15 +791,15 @@ uxa_acquire_drawable(ScreenPtr pScreen,
 	FreeScratchGC(pGC);
 
 	pDst = CreatePicture(0, &pPixmap->drawable,
-				 PictureMatchFormat(pScreen, depth, pSrc->format),
-				 0, 0, serverClient, &error);
+			     PictureMatchFormat(pScreen, depth, pSrc->format),
+			     0, 0, serverClient, &error);
 	pScreen->DestroyPixmap(pPixmap);
 	ValidatePicture(pDst);
 
 done:
 	pDst->componentAlpha = pSrc->componentAlpha;
-	*out_x = x;
-	*out_y = y;
+	*out_x = 0;
+	*out_y = 0;
 	return pDst;
 }
 
@@ -803,8 +819,8 @@ uxa_acquire_picture(ScreenPtr screen,
 			*out_x = x + src->pDrawable->x;
 			*out_y = y + src->pDrawable->y;
 		} else {
-			*out_x = 0;
-			*out_y = 0;
+			*out_x = x;
+			*out_y = y;
 		}
 		return src;
 	}
@@ -1436,21 +1452,6 @@ compatible_formats (CARD8 op, PicturePtr dst, PicturePtr src)
 	return 0;
 }
 
-static int
-drawable_contains (DrawablePtr drawable, int x, int y, int w, int h)
-{
-	if (x < 0 || y < 0)
-		return FALSE;
-
-	if (x + w > drawable->width)
-		return FALSE;
-
-	if (y + h > drawable->height)
-		return FALSE;
-
-	return TRUE;
-}
-
 void
 uxa_composite(CARD8 op,
 	      PicturePtr pSrc,