[PATCH] Fix errno codes set by opendir() in case of problems with the path argument

[Oleg Kravtsov <Oleg dot Kravtsov at oktetlabs dot ru>]

Currently cygwin has a problem with errno code set by opendir() 
function. It always sets errno to ENOENT.
After applying the path opendir() sets errno to 'ENAMETOOLONG' when path 
or a path component is too long,
'ELOOP' when a loop of symbolic links exits in the path.

Best regards,
Oleg

2014-02-18  Oleg Kravtsov <Oleg.Kravtsov@oktetlabs.ru>

       * dir.cc (opendir): Set errno code depending on the type of an error
       instead of always setting it to ENOENT.


Index: cygwin/dir.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/dir.cc,v
retrieving revision 1.136
diff -u -p -r1.136 dir.cc
--- cygwin/dir.cc	31 Jan 2014 19:27:26 -0000	1.136
+++ cygwin/dir.cc	3 Mar 2014 18:33:55 -0000
@@ -57,7 +57,16 @@ opendir (const char *name)
 
   fh = build_fh_name (name, PC_SYM_FOLLOW);
   if (!fh)
-    res = NULL;
+    {
+      res = NULL;
+      goto done;
+    }
+
+  if (fh->error ())
+    {
+      debug_printf ("got %d error from build_fh_name", fh->error ());
+      set_errno (fh->error ());
+    }
   else if (fh->exists ())
     res = fh->opendir (-1);
   else
@@ -71,6 +80,8 @@ opendir (const char *name)
   /* Applications calling flock(2) on dirfd(fd) need this... */
   if (res && !fh->nohandle ())
     fh->set_unique_id ();
+
+done:
   return res;
 }