Explicitly use and check for FD_CLOEXEC.

This may break places which have the FD_CLOEXEC functionality
but do not have the FD_CLOEXEC define.

In any case, using a boolean for the F_SETFD flag is icky.
Using an explicit 1 is also dubious.

1 files changed, 2 insertions, 2 deletions

diff --git a/perl.c b/perl.c
index 303e1f2c5c..64cc3957ff 100644
--- a/perl.c
+++ b/perl.c
@@ -3796,10 +3796,10 @@ S_open_script(pTHX_ const char *scriptname, bool dosearch, bool *suidscript)
 		    CopFILE(PL_curcop), Strerror(errno));
     }
     fd = PerlIO_fileno(rsfp);
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
     if (fd >= 0) {
         /* ensure close-on-exec */
-        if (fcntl(fd, F_SETFD, 1) < 0) {
+        if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0) {
             Perl_croak(aTHX_ "Can't open perl script \"%s\": %s\n",
                        CopFILE(PL_curcop), Strerror(errno));
         }