[newlib-cygwin] Cygwin: fhandler_base::fstat_fs: accomodate the O_PATH flag

[Ken Brown]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=74e6e881433c45e758582adfdcb4be20ad5b52a9

commit 74e6e881433c45e758582adfdcb4be20ad5b52a9
Author: Ken Brown <kbrown@cornell.edu>
Date:   Fri Jan 24 14:54:47 2020 -0500

    Cygwin: fhandler_base::fstat_fs: accomodate the O_PATH flag
    
    Treat a special file opened with O_PATH the same as a regular file,
    i.e., use its handle to get the stat information.
    
    Before this change, fstat_fs opened the file a second time, with the
    wrong flags and without closing the existing handle.  A side effect
    was to change the openflags of the file, possibly causing further
    system calls to fail.
    
    Currently this change only affects FIFOs, but it will affect
    AF_LOCAL/AF_UNIX sockets too once they support O_PATH.

Diff:
---
 winsup/cygwin/fhandler_disk_file.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index 197f04f..d9213d7 100644
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -359,7 +359,7 @@ fhandler_base::fstat_fs (struct stat *buf)
 
   if (get_stat_handle ())
     {
-      if (!nohandle () && !is_fs_special ())
+      if (!nohandle () && (!is_fs_special () || get_flags () & O_PATH))
 	res = pc.fs_is_nfs () ? fstat_by_nfs_ea (buf) : fstat_by_handle (buf);
       if (res)
 	res = fstat_by_name (buf);