dri: fromPlanar() can return NULL as a valid result

It was assumed that fromPlanar() could return NULL to mean
that the planar image is the same as the parent DRI image.
That assumption wasn't made everywhere though.

Let's fix things and make sure that all callers understand
a NULL result

Signed-off-by: Louis-Francis Ratté-Boulianne <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
Reviewed-by: Daniel Stone <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gbm/backends/dri/gbm_dri.c b/src/gbm/backends/dri/gbm_dri.c
index 0d088bd62b6..ed64ad61bf0 100644
--- a/src/gbm/backends/dri/gbm_dri.c
+++ b/src/gbm/backends/dri/gbm_dri.c
@@ -849,6 +849,7 @@ gbm_dri_bo_get_offset(struct gbm_bo *_bo, int plane)
       dri->image->queryImage(image, __DRI_IMAGE_ATTRIB_OFFSET, &offset);
       dri->image->destroyImage(image);
    } else {
+      assert(plane == 0);
       dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_OFFSET, &offset);
    }