From b1bb2520c80186cf18d44574cf1b204d1560f02f Mon Sep 17 00:00:00 2001
From: normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sun, 7 May 2017 07:38:30 +0000
Subject: [PATCH] io.c (do_fcntl): update max FD for F_DUPFD_CLOEXEC, too

Somebody may pass 1030 (the value of F_DUPFD_CLOEXEC) to IO#fcntl
because they copied code from somewhere else.  Ensure we know
about FDs created that way.

* io.c (do_fcntl): update max FD for F_DUPFD_CLOEXEC, too

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 io.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/io.c b/io.c
index 9f6c2fe871..c274c9b9fe 100644
--- a/io.c
+++ b/io.c
@@ -9480,11 +9480,17 @@ do_fcntl(int fd, int cmd, long narg)
     arg.narg = narg;
 
     retval = (int)rb_thread_io_blocking_region(nogvl_fcntl, &arg, fd);
+    if (retval != -1) {
+	switch (cmd) {
 #if defined(F_DUPFD)
-    if (retval != -1 && cmd == F_DUPFD) {
-	rb_update_max_fd(retval);
-    }
+	case F_DUPFD:
 #endif
+#if defined(F_DUPFD_CLOEXEC)
+	case F_DUPFD_CLOEXEC:
+#endif
+	    rb_update_max_fd(retval);
+	}
+    }
 
     return retval;
 }