[PATCH wayland] connection: Clear correct args when clearing fds to -1

[Derek Foreman]

commit 52609ddf79a96fee0465006e2c6339a3a5d23a87 was intended to
set fds to -1 in the arg list, however it failed to account for
version information at the start of signatures.

Most noticably, this broke mesa's create_prime_buffer by setting
width to -1 instead of the fd, as the width was the argument
following the fd, and the version was one byte long.

This should close https://bugs.kde.org/show_bug.cgi?id=389200

Signed-off-by: Derek Foreman <derekf at osg.samsung.com>
---
 src/connection.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/connection.c b/src/connection.c
index 6f83bab..5d5711f 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -533,10 +533,13 @@ wl_argument_from_va_list(const char *signature, union wl_argument *args,
 static void
 wl_closure_clear_fds(struct wl_closure *closure)
 {
+	const char *signature = closure->message->signature;
+	struct argument_details arg;
 	int i;
 
-	for (i = 0; closure->message->signature[i]; i++) {
-		if (closure->message->signature[i] == 'h')
+	for (i = 0; i < closure->count; i++) {
+		signature = get_next_argument(signature, &arg);
+		if (arg.type == 'h')
 			closure->args[i].h = -1;
 	}
 }
-- 
2.14.3