[COMMITTED 2/2] poked: enable FD_CLOEXEC flag the right way

[Mohammad-Reza Nabipoor]

Reported by Eric Blake.

2023-01-24  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * poked/usock.c (usock_new): Don't blindly set FD_CLOEXEC; first
        get the flags, enable the FD_CLOEXEC flag and set new the flag.
---
 ChangeLog     |  5 +++++
 poked/usock.c | 10 +++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0fd5b4ec..107f7cb1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2023-01-24  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * poked/usock.c (usock_new): Don't blindly set FD_CLOEXEC; first
+       get the flags, enable the FD_CLOEXEC flag and set new the flag.
+
 2023-01-24  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
 
        * libpoke/pkl-rt.pk (get_time): Renamed to `gettime'.
diff --git a/poked/usock.c b/poked/usock.c
index 28559b59..6edc4e88 100644
--- a/poked/usock.c
+++ b/poked/usock.c
@@ -621,6 +621,7 @@ usock_new (const char *path)
 {
   struct usock *u;
   struct sockaddr_un adr;
+  int flags;
 
   u = calloc (1, sizeof (*u));
   if (u == NULL)
@@ -635,9 +636,11 @@ usock_new (const char *path)
   u->pipefd[1] = -1;
   if (pipe (u->pipefd) == -1)
     goto error;
-  if (fcntl (u->pipefd[0], F_SETFD, FD_CLOEXEC) == -1)
+  if ((flags = fcntl (u->pipefd[0], F_GETFD)) == -1
+      || fcntl (u->pipefd[0], F_SETFD, flags | FD_CLOEXEC) == -1)
     goto error;
-  if (fcntl (u->pipefd[1], F_SETFD, FD_CLOEXEC) == -1)
+  if ((flags = fcntl (u->pipefd[1], F_GETFD)) == -1
+      || fcntl (u->pipefd[1], F_SETFD, flags | FD_CLOEXEC) == -1)
     goto error;
   if (fcntl (u->pipefd[0], F_SETFL, O_NONBLOCK) == -1)
     goto error;
@@ -645,7 +648,8 @@ usock_new (const char *path)
   if ((u->fd = socket (AF_UNIX, SOCK_STREAM, 0)) == -1)
     goto error;
 
-  if (fcntl (u->fd, F_SETFD, FD_CLOEXEC) == -1)
+  if ((flags = fcntl (u->fd, F_GETFD)) == -1
+      || fcntl (u->fd, F_SETFD, flags | FD_CLOEXEC) == -1)
     goto error;
   if (fcntl (u->fd, F_SETFL, O_NONBLOCK) == -1)
     goto error;
-- 
2.39.1