[PATCH] Cygwin: fstat_helper: always use handle in call to get_file_attribute

[Ken Brown]

When fhandler_base::fstat_helper is called, the handle h returned by
get_stat_handle() should be pc.handle() and should be safe to use for
getting the file information.  Previously, the call to
get_file_attribute() for FIFOs set the first argument to NULL instead
of h, thereby forcing the file to be opened for fetching the security
descriptor in get_file_sd().
---
 winsup/cygwin/fhandler_disk_file.cc | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index f362e31e3..ad63af824 100644
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -394,13 +394,14 @@ fhandler_base::fstat_fs (struct stat *buf)
   return res;
 }
 
+/* Called by fstat_by_handle and fstat_by_name. */
 int __reg2
 fhandler_base::fstat_helper (struct stat *buf)
 {
   IO_STATUS_BLOCK st;
   FILE_COMPRESSION_INFORMATION fci;
-  HANDLE h = get_stat_handle ();
-  PFILE_ALL_INFORMATION pfai = pc.fai ();
+  HANDLE h = get_stat_handle ();      /* Should always be pc.handle(). */
+  pfile_all_information pfai = pc.fai ();
   ULONG attributes = pc.file_attributes ();
 
   to_timestruc_t (&pfai->BasicInformation.LastAccessTime, &buf->st_atim);
@@ -475,8 +476,8 @@ fhandler_base::fstat_helper (struct stat *buf)
   else if (pc.issocket ())
     buf->st_mode = S_IFSOCK;
 
-  if (!get_file_attribute (is_fs_special () && !pc.issocket () ? NULL : h, pc,
-			   &buf->st_mode, &buf->st_uid, &buf->st_gid))
+  if (!get_file_attribute (h, pc, &buf->st_mode, &buf->st_uid,
+			   &buf->st_gid))
     {
       /* If read-only attribute is set, modify ntsec return value */
       if (::has_attribute (attributes, FILE_ATTRIBUTE_READONLY)
-- 
2.21.0