[PATCH 2/3] shm: Do not attempt mmap if no file descriptor was received

[Lubomir Rintel]

This is just for the sake of  cleanliness and correct error handling.
Without this the mmap would fail emitting an error message about failed
mapping to the client and a close of bogus file descriptor would be
attempted, which is harmless since it can not fail.

Signed-off-by: Lubomir Rintel <lkundrak at v3.sk>
---
 src/wayland-shm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/wayland-shm.c b/src/wayland-shm.c
index 28f52f4..ad92dba 100644
--- a/src/wayland-shm.c
+++ b/src/wayland-shm.c
@@ -220,6 +220,13 @@ shm_create_pool(struct wl_client *client, struct wl_resource *resource,
 {
 	struct wl_shm_pool *pool;
 
+	if (fd < 0) {
+		wl_resource_post_error(resource,
+				       WL_SHM_ERROR_INVALID_FD,
+				       "file descriptor expected");
+		return;
+	}
+
 	pool = malloc(sizeof *pool);
 	if (pool == NULL) {
 		wl_client_post_no_memory(client);
-- 
1.8.4.2