[Libguestfs] [nbdkit PATCH] nbd: Silence compiler warning

[Eric Blake]

gcc has a false positive warning, which fails a build with -Werror:

nbd.c: In function ‘nbd_reply’:
nbd.c:306:19: error: ‘trans.cookie’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
   assert (err < 0 || cookie == trans.cookie);
                   ^~
cc1: all warnings being treated as errors

The problem is that gcc can't tell that nbd_reply_raw()'s early
return path via nbd_mark_dead() prior to initializing trans
will always set err to a negative value.  Help it out by manually
initializing trans.

Signed-off-by: Eric Blake <eblake at redhat.com>
---

Pushing as the obvious fix for the warning.

 plugins/nbd/nbd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/nbd/nbd.c b/plugins/nbd/nbd.c
index c3ca4ed..739eecd 100644
--- a/plugins/nbd/nbd.c
+++ b/plugins/nbd/nbd.c
@@ -300,7 +300,7 @@ static int
 nbd_reply (struct handle *h, int cookie)
 {
   int err;
-  struct transaction trans;
+  struct transaction trans = { 0 };

   err = nbd_reply_raw (h, &trans);
   assert (err < 0 || cookie == trans.cookie);
-- 
2.13.6