[newlib-cygwin] Cygwin: proc fd: return EACCES for HANDLE-less fds

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=8ae26f96ae710f8562162fd5d4e9a5d7434beb7b

commit 8ae26f96ae710f8562162fd5d4e9a5d7434beb7b
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Sun Jan 13 23:09:48 2019 +0100

    Cygwin: proc fd: return EACCES for HANDLE-less fds
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/fhandler_process_fd.cc | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/winsup/cygwin/fhandler_process_fd.cc b/winsup/cygwin/fhandler_process_fd.cc
index a3691d9..a33fd75 100644
--- a/winsup/cygwin/fhandler_process_fd.cc
+++ b/winsup/cygwin/fhandler_process_fd.cc
@@ -69,6 +69,13 @@ fhandler_process_fd::fetch_fh (HANDLE &out_hdl, uint32_t flags)
 	}
       hdl = pc.deserialize (buf);
     }
+  if (hdl == NULL)
+    {
+      if (proc != GetCurrentProcess ())
+	CloseHandle (proc);
+      set_errno (EACCES);
+      return NULL;
+    }
   BOOL ret = DuplicateHandle (proc, hdl, GetCurrentProcess (), &hdl,
 			      0, FALSE, DUPLICATE_SAME_ACCESS);
   if (proc != GetCurrentProcess ())