From: Chris Hanson <org/chris-hanson/cph>
Date: Mon, 22 Jan 1990 23:39:37 +0000 (+0000)
Subject: Change `operation/open' to handle #F as a result from
X-Git-Tag: 20090517-FFI~11572
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=ca101973ac24965674b04528236bb785e1f14beb;p=mit-scheme.git

Change `operation/open' to handle #F as a result from
`starbase-open-device'.
---

diff --git a/v7/src/runtime/graphics.scm b/v7/src/runtime/graphics.scm
index 6b280d502..40af5be47 100644
--- a/v7/src/runtime/graphics.scm
+++ b/v7/src/runtime/graphics.scm
@@ -1,8 +1,8 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/graphics.scm,v 1.2 1989/06/27 10:18:01 cph Rel $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/graphics.scm,v 1.3 1990/01/22 23:39:37 cph Rel $
 
-Copyright (c) 1989 Massachusetts Institute of Technology
+Copyright (c) 1989, 1990 Massachusetts Institute of Technology
 
 This material was developed by the Scheme project at the Massachusetts
 Institute of Technology, Department of Electrical Engineering and
@@ -183,9 +183,10 @@ MIT in each case. |#
   (buffer? false))
 
 (define (make-graphics-device type . arguments)
-  (%make-graphics-device type
-			 (apply (graphics-device-type/operation/open type)
-				arguments)))
+  (let ((descriptor
+	 (apply (graphics-device-type/operation/open type) arguments)))
+    (and descriptor
+	 (%make-graphics-device type descriptor))))
 
 (let-syntax
     ((define-graphics-operation
diff --git a/v7/src/runtime/starbase.scm b/v7/src/runtime/starbase.scm
index 0d4c3efc9..3bc8f4e24 100644
--- a/v7/src/runtime/starbase.scm
+++ b/v7/src/runtime/starbase.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/starbase.scm,v 1.3 1990/01/17 05:04:24 gjs Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/starbase.scm,v 1.4 1990/01/22 23:36:36 cph Rel $
 
 Copyright (c) 1989, 1990 Massachusetts Institute of Technology
 
@@ -115,15 +115,15 @@ MIT in each case. |#
   (implemented-primitive-procedure? starbase-open-device))
 
 (define (operation/open device-name driver-name)
-  (let ((device
-	 (make-starbase-device
-	  (starbase-open-device device-name driver-name))))
-    (operation/set-coordinate-limits device -1 -1 1 1)
-    (operation/set-text-height device 0.1)
-    (operation/set-text-aspect device 1)
-    (operation/set-text-slant device 0)
-    (operation/set-text-rotation device 0)
-    device))
+  (let ((descriptor (starbase-open-device device-name driver-name)))
+    (and descriptor
+	 (let ((device (make-starbase-device descriptor)))
+	   (operation/set-coordinate-limits device -1 -1 1 1)
+	   (operation/set-text-height device 0.1)
+	   (operation/set-text-aspect device 1)
+	   (operation/set-text-slant device 0)
+	   (operation/set-text-rotation device 0)
+	   device))))
 
 (define (operation/close device)
   (starbase-close-device (starbase-device/descriptor device)))