From: Jarkko Hietaniemi <jhi@iki.fi>
Date: Wed, 26 Aug 2015 12:53:45 +0000 (-0400)
Subject: Note that the all the fd flags are saved/restored.
X-Git-Tag: if-0.0605~145
X-Git-Url: https://perl5.git.perl.org/perl5.git/commitdiff_plain/5798d63101f7b13bd5aaf5a5bf429a8e08991016?ds=sidebyside

Note that the all the fd flags are saved/restored.

FD_CLOEXEC is currently usually the only defined fd flag
for F_GETFD/F_SETFD, but let's not assume that.
---

diff --git a/doio.c b/doio.c
index 39e5ce7..1b1e951 100644
--- a/doio.c
+++ b/doio.c
@@ -741,9 +741,10 @@ S_openn_cleanup(pTHX_ GV *gv, IO *io, PerlIO *fp, char *mode, const char *oname,
                 int ofd = PerlIO_fileno(fp);
                 int dupfd = ofd >= 0 ? PerlLIO_dup(ofd) : -1;
 #if defined(HAS_FCNTL) && defined(F_SETFD)
-		/* Assume if we have F_SETFD we have F_GETFD */
-                int coe = ofd >= 0 ? fcntl(ofd, F_GETFD) : -1;
-                if (coe < 0) {
+		/* Assume if we have F_SETFD we have F_GETFD. */
+                /* Get a copy of all the fd flags. */
+                int fd_flags = ofd >= 0 ? fcntl(ofd, F_GETFD) : -1;
+                if (fd_flags < 0) {
                     if (dupfd >= 0)
                         PerlLIO_close(dupfd);
                     goto say_false;
@@ -757,8 +758,9 @@ S_openn_cleanup(pTHX_ GV *gv, IO *io, PerlIO *fp, char *mode, const char *oname,
                 PerlIO_close(fp);
                 PerlLIO_dup2(dupfd, ofd);
 #if defined(HAS_FCNTL) && defined(F_SETFD)
-		/* The dup trick has lost close-on-exec on ofd */
-		fcntl(ofd,F_SETFD, coe);
+		/* The dup trick has lost close-on-exec on ofd,
+                 * and possibly any other flags, so restore them. */
+		fcntl(ofd,F_SETFD, fd_flags);
 #endif
                 PerlLIO_close(dupfd);
 	    }