[PATCH] mkdir: always check-for-existence

[Ben]

When creating a directory which already exists, NtCreateFile will correctly
return 'STATUS_OBJECT_NAME_COLLISION'.

However when creating a directory and all its parents a normal use would
be to start with mkdir(‘/cygdrive/c’) which translates to ‘C:\’ for 
which it'll
instead return ‘STATUS_ACCESS_DENIED’.

So we better check for existence prior to calling NtCreateFile.
---
 Â winsup/cygwin/dir.cc | 4 +++-
 Â 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/dir.cc b/winsup/cygwin/dir.cc
index f43eae461..b757851d5 100644
--- a/winsup/cygwin/dir.cc
+++ b/winsup/cygwin/dir.cc
@@ -331,8 +331,10 @@ mkdir (const char *dir, mode_t mode)
 Â Â Â  Â Â  debug_printf ("got %d error from build_fh_name", fh->error ());
 Â Â Â  Â Â  set_errno (fh->error ());
 Â Â Â  Â }
+Â Â Â Â Â  else if (fh->exists ())
+Â Â  Â set_errno (EEXIST);
 Â Â Â Â Â Â  else if (has_dot_last_component (dir, true))
-Â Â  Â set_errno (fh->exists () ? EEXIST : ENOENT);
+Â Â  Â set_errno (ENOENT);
 Â Â Â Â Â Â  else if (!fh->mkdir (mode))
 Â Â Â  Â res = 0;
 Â Â Â Â Â Â  delete fh;

-- 
2.21.0