Fix instance of "point not visible at end of redisplay" error that

Matt Birkholz pointed out.  Change code that generates this error to
conditionally force the point to be visible; this results in more
robust behavior.

diff --git a/v7/src/edwin/bufwin.scm b/v7/src/edwin/bufwin.scm
index 889f7d403e1d74306a59f97befd5dbdbaaae98b2..a6849e78d41b0124692c94f95beda32cc974fafb 100644 (file)
--- a/v7/src/edwin/bufwin.scm
+++ b/v7/src/edwin/bufwin.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Id: bufwin.scm,v 1.300 1993/01/16 05:15:30 cph Exp $
+;;;    $Id: bufwin.scm,v 1.301 1993/08/18 23:57:38 cph Exp $
 ;;;
 ;;;    Copyright (c) 1986, 1989-93 Massachusetts Institute of Technology
 ;;;
@@ -966,7 +966,8 @@ This number is a percentage, where 0 is the window's top and 100 the bottom."
             (let ((mask (set-interrupt-enables! interrupt-mask/gc-ok)))
               (%set-window-point-index!
                window
-               (or (predict-index window start y-start 0 point-y)
+               (or (predict-index window start y-start
+                                  (vector-ref cws 4) point-y)
                    (%window-group-end-index window)))
               (set-window-start! window cws)
               (set-interrupt-enables! mask)
@@ -1198,9 +1199,23 @@ If this is zero, point is always centered after it moves off screen."
 
 (define (update-cursor! window)
   (let ((xy (buffer-window/point-coordinates window)))
-    (if (not (and (fix:<= 0 (car xy))
-                 (fix:< (car xy) (window-x-size window))
-                 (fix:<= 0 (cdr xy))
-                 (fix:< (cdr xy) (window-y-size window))))
-       (error "point not visible at end of redisplay"))
-    (set-inferior-position! (%window-cursor-inferior window) xy)))
\ No newline at end of file
+    (if (and (fix:<= 0 (car xy))
+            (fix:< (car xy) (window-x-size window))
+            (fix:<= 0 (cdr xy))
+            (fix:< (cdr xy) (window-y-size window)))
+       (set-inferior-position! (%window-cursor-inferior window) xy)
+       (begin
+         (if point-not-visible-error?
+             (error "point not visible at end of redisplay"))
+         (%set-window-point-index!
+          window
+          (or (predict-index window
+                             (%window-start-line-index window)
+                             (%window-start-line-y window)
+                             (%window-start-partial window)
+                             0)
+              (%window-group-end-index window)))
+         (update-cursor! window)))))
+
+(define point-not-visible-error?
+  #f)
\ No newline at end of file