st/mesa: do not call update_framebuffer_size with NULL pointer

In st_renderbuffer_alloc_storage, we avoid allocating storage for
zero-sized buffers, leading to this pointer being NULL. We already
take care to avoid dereferencing these pointers for color-buffers,
but not for depth/stencil-buffers.

So let's thread a bit more carefully here.

This avoids a crash while running Piglit's glx/glx-visuals-stencil
test, both on virgl and r600g.

Signed-off-by: Erik Faye-Lund <[email protected]>
Reviewed-by: Guillaume Charifi <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/mesa/state_tracker/st_atom_framebuffer.c b/src/mesa/state_tracker/st_atom_framebuffer.c
index 807c312a5db..a0dd0d1f649 100644
--- a/src/mesa/state_tracker/st_atom_framebuffer.c
+++ b/src/mesa/state_tracker/st_atom_framebuffer.c
@@ -181,7 +181,8 @@ st_update_framebuffer_state( struct st_context *st )
          st_update_renderbuffer_surface(st, strb);
       }
       framebuffer.zsbuf = strb->surface;
-      update_framebuffer_size(&framebuffer, strb->surface);
+      if (strb->surface)
+         update_framebuffer_size(&framebuffer, strb->surface);
    }
    else
       framebuffer.zsbuf = NULL;