diff -urbB emacs21-21.4a/src/emacs.c emacs21-21.4a.displaylenience/src/emacs.c
--- emacs21-21.4a/src/emacs.c	2002-08-29 20:27:07.000000000 +0100
+++ emacs21-21.4a.displaylenience/src/emacs.c	2006-03-06 00:05:23.000000000 +0000
@@ -45,6 +45,10 @@
 #include "intervals.h"
 #include "buffer.h"
 
+#ifdef HAVE_X_WINDOWS
+#include "xterm.h"
+#endif
+
 #include "systty.h"
 #include "blockinput.h"
 #include "syssignal.h"
@@ -1268,6 +1272,14 @@
 
     /* Don't actually discard this arg.  */
     skip_args = count_before;
+    
+    /* Do NOT be lenient if the user explicitly asked for a named display */
+    if( display_arg != 1 )
+      if( x_display_ok(displayname) == 0 ) {
+        inhibit_window_system = 1;
+        fprintf( stderr,
+                 "DISPLAY unavailable, simulating -nw\n", displayname );
+      }
   }
 #endif
 
diff -urbB emacs21-21.4a/src/xterm.c emacs21-21.4a.displaylenience/src/xterm.c
--- emacs21-21.4a/src/xterm.c	2002-10-15 15:21:45.000000000 +0100
+++ emacs21-21.4a.displaylenience/src/xterm.c	2006-03-06 00:07:40.000000000 +0000
@@ -14156,6 +14156,24 @@
 }
 #endif
 
+int
+x_display_ok (display)
+    const char * display;
+{
+    int dpy_ok = 1;
+    Display *dpy;
+    char *display_name = display || getenv("DISPLAY");
+
+    if( !display_name ) 
+      return 0;
+
+    if( dpy = XOpenDisplay (display) )
+      XCloseDisplay( dpy );
+    else
+      dpy_ok = 0;
+    return dpy_ok;
+}
+
 struct x_display_info *
 x_term_init (display_name, xrm_option, resource_name)
      Lisp_Object display_name;
diff -urbB emacs21-21.4a/src/xterm.h emacs21-21.4a.displaylenience/src/xterm.h
--- emacs21-21.4a/src/xterm.h	2002-02-22 10:41:44.000000000 +0000
+++ emacs21-21.4a.displaylenience/src/xterm.h	2006-03-06 00:07:40.000000000 +0000
@@ -378,6 +378,7 @@
 extern struct x_display_info *x_display_info_for_name P_ ((Lisp_Object));
 
 extern struct x_display_info *x_term_init P_ ((Lisp_Object, char *, char *));
+extern int x_display_ok  P_ ((const char *));
 
 extern Lisp_Object x_list_fonts P_ ((struct frame *, Lisp_Object, int, int));
 extern void select_visual P_ ((struct x_display_info *));