[newlib-cygwin] Cygwin: path_conv::check: handle error from fhandler_process::exists

[Ken Brown <kbrown@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=6775ac8cb5adf6c945c5d09d957f21d2ca673aba

commit 6775ac8cb5adf6c945c5d09d957f21d2ca673aba
Author: Ken Brown <kbrown@cornell.edu>
Date:   Tue Sep 8 12:23:32 2020 -0400

    Cygwin: path_conv::check: handle error from fhandler_process::exists
    
    fhandler_process::exists is called when we are checking a path
    starting with "/proc/<pid>/fd".  If it returns virt_none and sets an
    errno, there is no need for further checking.  Just set 'error' and
    return.

Diff:
---
 winsup/cygwin/path.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 95faf8ca7..1d0c38a20 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -809,6 +809,15 @@ path_conv::check (const char *src, unsigned opt,
 			  delete fh;
 			  goto retry_fs_via_processfd;
 			}
+		      else if (file_type == virt_none && dev == FH_PROCESSFD)
+			{
+			  error = get_errno ();
+			  if (error)
+			    {
+			      delete fh;
+			      return;
+			    }
+			}
 		      delete fh;
 		    }
 		  switch (file_type)