[qemu-xen stable-4.14] qemu-nbd: Close inherited stderr

[patchbot@xxxxxxx]

commit bdac9aabd92bd8e6d070cbc83e46272e86f63dc5
Author:     Raphael Pour <raphael.pour@xxxxxxxxxxx>
AuthorDate: Fri May 15 08:36:07 2020 +0200
Commit:     Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
CommitDate: Mon Aug 24 18:55:45 2020 -0500

    qemu-nbd: Close inherited stderr
    
    Close inherited stderr of the parent if fork_process is false.
    Otherwise no one will close it. (introduced by e6df58a5)
    
    This only affected 'qemu-nbd -c /dev/nbd0'.
    
    Signed-off-by: Raphael Pour <raphael.pour@xxxxxxxxxxx>
    Message-Id: <d8ddc993-9816-836e-a3de-c6edab9d9c49@xxxxxxxxxxx>
    Reviewed-by: Eric Blake <eblake@xxxxxxxxxx>
    [eblake: Enhance commit message]
    Signed-off-by: Eric Blake <eblake@xxxxxxxxxx>
    (cherry picked from commit 0eaf453ebf6788885fbb5d40426b154ef8805407)
    Signed-off-by: Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
---
 qemu-nbd.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 4aa005004e..306e44fb0a 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -916,7 +916,11 @@ int main(int argc, char **argv)
         } else if (pid == 0) {
             close(stderr_fd[0]);
 
-            old_stderr = dup(STDERR_FILENO);
+            /* Remember parent's stderr if we will be restoring it. */
+            if (fork_process) {
+                old_stderr = dup(STDERR_FILENO);
+            }
+
             ret = qemu_daemon(1, 0);
 
             /* Temporarily redirect stderr to the parent's pipe...  */
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#stable-4.14