[PATCH wayland] assert if a listener function is NULL

[Ryo Munakata]

Signed-off-by: Ryo Munakata <ryomnktml at gmail.com>
---
 src/connection.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/connection.c b/src/connection.c
index f292853..c61275d 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -931,6 +931,11 @@ wl_closure_invoke(struct wl_closure *closure, uint32_t flags,
 		     count + 2, &ffi_type_void, ffi_types);
 
 	implementation = target->implementation;
+	if (!implementation[opcode]) {
+		wl_log("listener function for opcode %u is NULL\n",
+				opcode);
+		assert(implementation[opcode] != NULL);
+	}
 	ffi_call(&cif, implementation[opcode], NULL, ffi_args);
 }
 
-- 
2.1.2