Allow first argument to MAKE-GRAPHICS-DEVICE to be optional.

diff --git a/v7/src/runtime/graphics.scm b/v7/src/runtime/graphics.scm
index c4fc1ff6f2cbde30be1484da4dca997369e24a48..507a43276eb7f10f5edb0e9be64352915baf1753 100644 (file)
--- a/v7/src/runtime/graphics.scm
+++ b/v7/src/runtime/graphics.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: graphics.scm,v 1.11 1994/03/01 21:18:28 cph Exp $
+$Id: graphics.scm,v 1.12 1994/04/22 04:45:40 cph Exp $
 
 Copyright (c) 1989-94 Massachusetts Institute of Technology
 
@@ -223,12 +223,14 @@ MIT in each case. |#
   (buffer? false)
   (properties (make-1d-table) read-only true))
 
-
-(define (make-graphics-device type-name . arguments)
+(define (make-graphics-device #!optional type-name . arguments)
   (let ((type
-        (cond ((graphics-device-type? type-name) type-name)
-              ((not type-name) (get-default-graphics-device-type))
-              (else (lookup-graphics-device-type type-name)))))
+        (cond ((or (default-object? type-name) (not type-name))
+               (get-default-graphics-device-type))
+              ((graphics-device-type? type-name)
+               type-name)
+              (else
+               (lookup-graphics-device-type type-name)))))
     (let ((descriptor
           (apply (graphics-device-type/operation/open type) arguments)))
       (and descriptor