[PATCH xserver 1/4] dri3: Fix error handling in dri3_buffer_from_pixmap request.

[Mario Kleiner]

The old info->fd_from_pixmap() driver hook, which is
preferentially used in dri3_fd_from_pixmap(), can return
error codes other than -1, e.g., -EINVAL (-22) on nouveau-ddx.

Not handling the error causes a broken/corrupted X-Connection
resulting from a failed request.

This fixes failure of sddm-greeter to start up under nouveau-ddx
with DRI3 enabled and DRI3 protocol version properly clamped
to 1.0 by the server (see followup patch).

Fixes: 75bba3aedcb0 ("dri3: Use single-FD screen call for single-FD request")
Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
Cc: Daniel Stone <daniels at collabora.com>
Cc: Adam Jackson <ajax at redhat.com>
---
 dri3/dri3_request.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dri3/dri3_request.c b/dri3/dri3_request.c
index 8b35036..61d3f9d 100644
--- a/dri3/dri3_request.c
+++ b/dri3/dri3_request.c
@@ -255,7 +255,7 @@ proc_dri3_buffer_from_pixmap(ClientPtr client)
     rep.bpp = pixmap->drawable.bitsPerPixel;
 
     fd = dri3_fd_from_pixmap(pixmap, &rep.stride, &rep.size);
-    if (fd == -1)
+    if (fd < 0)
         return BadPixmap;
 
     if (client->swapped) {
-- 
2.7.4