From: Chris Hanson <org/chris-hanson/cph>
Date: Sat, 2 Jun 2001 22:25:38 +0000 (+0000)
Subject: Add logic to GET-X-DISPLAY to test for existence of X primitives, and
X-Git-Tag: 20090517-FFI~2742
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=47882eab8cfaf72ace51ea407be296f727b1bd3c;p=mit-scheme.git

Add logic to GET-X-DISPLAY to test for existence of X primitives, and
to make sure that a display variable exists.  This is necessary so
that Edwin will work on a system that doesn't have X support.
---

diff --git a/v7/src/edwin/xterm.scm b/v7/src/edwin/xterm.scm
index 6d7f5cce3..afb1ed637 100644
--- a/v7/src/edwin/xterm.scm
+++ b/v7/src/edwin/xterm.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: xterm.scm,v 1.66 2001/03/21 19:25:42 cph Exp $
+;;; $Id: xterm.scm,v 1.67 2001/06/02 22:25:38 cph Exp $
 ;;;
 ;;; Copyright (c) 1989-2001 Massachusetts Institute of Technology
 ;;;
@@ -1324,10 +1324,12 @@
   ;; X-OPEN-DISPLAY hangs, uninterruptibly, when the X server is
   ;; running the login loop of xdm.  Can this be fixed?
   (or x-display-data
-      (let ((display (x-open-display x-display-name)))
-	(set! x-display-data display)
-	(set! x-display-events (make-queue))
-	display)))
+      (and (implemented-primitive-procedure? x-open-display)
+	   (or x-display-name (get-environment-variable "DISPLAY"))
+	   (let ((display (x-open-display x-display-name)))
+	     (set! x-display-data display)
+	     (set! x-display-events (make-queue))
+	     display))))
 
 (define (initialize-package!)
   (set! screen-list '())