From fb859603163458157f107bae728cfefabff41c1a Mon Sep 17 00:00:00 2001
From: "Richard M. Stallman" <rms@gnu.org>
Date: Sun, 5 May 1996 18:52:57 +0000
Subject: [PATCH] (Fmsdos_long_file_names): New function. (syms_of_dosfns):
 defsubr it.

---
 src/dosfns.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/dosfns.c b/src/dosfns.c
index 6030f0696c3..11e30c07591 100644
--- a/src/dosfns.c
+++ b/src/dosfns.c
@@ -241,6 +241,18 @@ Return nil if startup screen is not available.")
   return Qt;
 }
 
+DEFUN ("msdos-long-file-names", Fmsdos_long_file_names, Smsdos_long_file_names,
+  0, 0, 0,
+  "Return non-nil if long file names are supported. on MSDOS.")
+  ()
+{
+#if __DJGPP__ >= 2
+  return (! NILP (Fgetenv ("LFN")) ? Qt : Qnil);
+#else
+  return Qnil;
+#endif
+}
+
 
 /* country info */
 int dos_country_code;
@@ -320,6 +332,7 @@ syms_of_dosfns ()
   defsubr (&Smsdos_set_keyboard);
   defsubr (&Sinsert_startup_screen);
   defsubr (&Smsdos_mouse_disable);
+  defsubr (&Smsdos_long_file_names);
 #ifndef HAVE_X_WINDOWS
   defsubr (&Smsdos_mouse_p);
   defsubr (&Sset_mouse_position);
-- 
2.39.2