[PATCH xf86-video-mga] Composite fixup

[Connor Behan]

A driver like this that tries to composite a lot will definitely need to
avoid crashing for solid pictures.

Signed-off-by: Connor Behan <connor.behan at gmail.com>
---
 src/mga_exa.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/mga_exa.c b/src/mga_exa.c
index a011c91..c4e4d90 100644
--- a/src/mga_exa.c
+++ b/src/mga_exa.c
@@ -318,6 +318,11 @@ mgaGetTexFormat(PicturePtr pPict)
 static Bool
 mgaCheckSourceTexture(int tmu, PicturePtr pPict)
 {
+    if (!pPict->pDrawable) {
+        DEBUG_MSG(("Solid / gradient pictures not supported\n"));
+        return FALSE;
+    }
+
     int w = pPict->pDrawable->width;
     int h = pPict->pDrawable->height;
 
@@ -354,7 +359,7 @@ static Bool
 mgaCheckComposite(int op, PicturePtr pSrcPict, PicturePtr pMaskPict,
                   PicturePtr pDstPict)
 {
-    MGAPtr pMga = xf86ScreenToScrn(pSrcPict->pDrawable->pScreen)->driverPrivate;
+    MGAPtr pMga = xf86ScreenToScrn(pDstPict->pDrawable->pScreen)->driverPrivate;
 
     if (op >= sizeof(mgaBlendOp) / sizeof(mgaBlendOp[0])) {
         DEBUG_MSG(("unsupported op %x\n", op));
@@ -521,6 +526,7 @@ mgaPrepareComposite(int op, PicturePtr pSrcPict, PicturePtr pMaskPict,
 {
     PMGA(pDst);
     CARD32 fcol = 0xff000000, ds0 = 0, ds1 = 0, cmd, blendcntl;
+    if (!pSrc || !pSrcPict->pDrawable) return FALSE;
 
     mgaSetup(pMga, pDst, pDstPict, 2);
     OUTREG(MGAREG_DSTORG, exaGetPixmapOffset(pDst));
-- 
2.5.0