From 6ac063d10e060e0664b5d48cf9f44fbc220f1cfa Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Sat, 5 Mar 2022 12:52:04 -0500
Subject: [PATCH] process: only use F_DUPFD_CLOEXEC if it is defined (#3512)

We can save a syscall on most modern systems (required by POSIX 2008),
but not on all systems.

Also handle errors from CLOEXEC. Even though fcntl does not really
define there to be any, it could theoretically be EBADF if the user
happened to pass a bad file descriptor to the same number fd (such that
no other code happened to already fail on that).
---
 src/unix/process.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/unix/process.c b/src/unix/process.c
index e634209b..ead54334 100644
--- a/src/unix/process.c
+++ b/src/unix/process.c
@@ -275,9 +275,20 @@ static void uv__process_child_init(const uv_process_options_t* options,
     use_fd = pipes[fd][1];
     if (use_fd < 0 || use_fd >= fd)
       continue;
+#ifdef F_DUPFD_CLOEXEC /* POSIX 2008 */
     pipes[fd][1] = fcntl(use_fd, F_DUPFD_CLOEXEC, stdio_count);
+#else
+    pipes[fd][1] = fcntl(use_fd, F_DUPFD, stdio_count);
+#endif
     if (pipes[fd][1] == -1)
       uv__write_errno(error_fd);
+#ifndef F_DUPFD_CLOEXEC /* POSIX 2008 */
+    n = uv__cloexec_fcntl(pipes[fd][1], 1);
+    if (n) {
+      uv__write_int(error_fd, n);
+      _exit(127);
+    }
+#endif
   }
 
   for (fd = 0; fd < stdio_count; fd++) {
@@ -300,8 +311,13 @@ static void uv__process_child_init(const uv_process_options_t* options,
     }
 
     if (fd == use_fd) {
-      if (close_fd == -1)
-        uv__cloexec_fcntl(use_fd, 0);
+      if (close_fd == -1) {
+        n = uv__cloexec_fcntl(use_fd, 0);
+        if (n) {
+          uv__write_int(error_fd, n);
+          _exit(127);
+        }
+      }
     }
     else {
       fd = dup2(use_fd, fd);