[newlib-cygwin] Cygwin: FIFO: tweak fcntl and dup when O_PATH is set

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7d68ffadd3fbc9b8dcd189d4a20c12a9cd1ed743

commit 7d68ffadd3fbc9b8dcd189d4a20c12a9cd1ed743
Author: Ken Brown <kbrown@cornell.edu>
Date:   Thu Jan 23 16:31:05 2020 +0000

    Cygwin: FIFO: tweak fcntl and dup when O_PATH is set
    
    fhandler_fifo::fcntl and fhandler_fifo::dup now call the corresponding
    fhandler_base methods if the FIFO was opened with the O_PATH flag.

Diff:
---
 winsup/cygwin/fhandler_fifo.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index 8cbab35..a338f12 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -997,7 +997,7 @@ fhandler_fifo::close ()
 int
 fhandler_fifo::fcntl (int cmd, intptr_t arg)
 {
-  if (cmd != F_SETFL || nohandle ())
+  if (cmd != F_SETFL || nohandle () || (get_flags () & O_PATH))
     return fhandler_base::fcntl (cmd, arg);
 
   const bool was_nonblocking = is_nonblocking ();
@@ -1014,6 +1014,9 @@ fhandler_fifo::dup (fhandler_base *child, int flags)
   int ret = -1;
   fhandler_fifo *fhf = NULL;
 
+  if (get_flags () & O_PATH)
+    return fhandler_base::dup (child, flags);
+
   if (fhandler_base::dup (child, flags))
     goto out;