Fix bug in redisplay: when narrowing or widening a buffer, its windows

sometimes got confused, which could produce various errors.

diff --git a/v7/src/edwin/bufwin.scm b/v7/src/edwin/bufwin.scm
index 21b271cecd262e567310206de355e294a2a6b3dd..95f8f99d9dbddea6a7ff6d0f4ff1e4573893e9db 100644 (file)
--- a/v7/src/edwin/bufwin.scm
+++ b/v7/src/edwin/bufwin.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwin.scm,v 1.287 1991/02/15 18:12:31 cph Exp $
+;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwin.scm,v 1.288 1991/03/15 23:47:42 cph Exp $
 ;;;
 ;;;    Copyright (c) 1986, 1989-91 Massachusetts Institute of Technology
 ;;;
@@ -461,7 +461,7 @@
         (group-display-end (mark-group mark)))
        (else
         mark)))
-\f
+
 ;;;; Utilities
 
 (define-integrable (%window-extract-string window start end)
@@ -470,13 +470,6 @@
 (define-integrable (%window-modeline-event! window type)
   (window-modeline-event! (window-superior window) type))
 
-(define-integrable (set-mark-index! mark index)
-  (set-mark-position!
-   mark
-   (group-index->position-integrable (mark-group mark)
-                                    index
-                                    (mark-left-inserting? mark))))
-
 (define-integrable (fix:max x y)
   (if (fix:> x y) x y))
 
@@ -776,7 +769,8 @@
   (if (fix:= y-start 0)
       (if (%window-start-line-mark window)
          (begin
-           (set-mark-index! (%window-start-line-mark window) start-line)
+           (set-mark-index-integrable! (%window-start-line-mark window)
+                                       start-line)
            (if (not (eq? (%window-start-line-mark window)
                          (%window-start-mark window)))
                (begin
@@ -792,13 +786,15 @@
       (let ((start (predict-start-index window start-line y-start)))
        (if (%window-start-line-mark window)
            (begin
-             (set-mark-index! (%window-start-line-mark window) start-line)
+             (set-mark-index-integrable! (%window-start-line-mark window)
+                                         start-line)
              (if (eq? (%window-start-line-mark window)
                       (%window-start-mark window))
                  (%set-window-start-mark!
                   window
                   (%make-permanent-mark (%window-group window) start false))
-                 (set-mark-index! (%window-start-mark window) start)))
+                 (set-mark-index-integrable! (%window-start-mark window)
+                                             start)))
            (let ((group (%window-group window)))
              (%set-window-start-line-mark!
               window
@@ -822,40 +818,40 @@
   (without-interrupts (lambda () (%guarantee-start-mark! window))))
 
 (define (%guarantee-start-mark! window)
-  (let ((point-at!
-        (lambda (y)
-          (with-values
-              (lambda ()
-                (predict-start-line window (%window-point-index window) y))
-            (lambda (start y-start)
-              (set-start-mark! window start y-start))))))
-    (let ((recenter! (lambda () (point-at! (buffer-window/y-center window)))))
-      (cond ((not (%window-start-line-mark window))
-            (recenter!))
-           ((eq? (%window-point-moved? window) 'SINCE-START-SET)
-            (let ((y
-                   (predict-y window
-                              (%window-start-line-index window)
-                              (%window-start-line-y window)
-                              (%window-point-index window))))
-              (cond ((fix:< y 0)
-                     (let ((y (fix:+ y (ref-variable scroll-step))))
-                       (if (fix:< y 0)
-                           (recenter!)
-                           (point-at! y))))
-                    ((fix:>= y (window-y-size window))
-                     (let ((y (fix:- y (ref-variable scroll-step))))
-                       (if (fix:>= y (window-y-size window))
-                           (recenter!)
-                           (point-at! y)))))))))))
+  (let* ((index-at!
+         (lambda (index y)
+           (with-values (lambda () (predict-start-line window index y))
+             (lambda (start y-start)
+               (set-start-mark! window start y-start)))))
+        (point-at! (lambda (y) (index-at! (%window-point-index window) y)))
+        (recenter! (lambda () (point-at! (buffer-window/y-center window)))))
+    (cond ((not (%window-start-line-mark window))
+          (recenter!))
+         ((not (%window-line-start-index? window
+                                          (%window-start-line-index window)))
+          (index-at! (%window-start-index window) 0))
+         ((eq? (%window-point-moved? window) 'SINCE-START-SET)
+          (let ((y
+                 (predict-y window
+                            (%window-start-line-index window)
+                            (%window-start-line-y window)
+                            (%window-point-index window))))
+            (cond ((fix:< y 0)
+                   (let ((y (fix:+ y (ref-variable scroll-step))))
+                     (if (fix:< y 0)
+                         (recenter!)
+                         (point-at! y))))
+                  ((fix:>= y (window-y-size window))
+                   (let ((y (fix:- y (ref-variable scroll-step))))
+                     (if (fix:>= y (window-y-size window))
+                         (recenter!)
+                         (point-at! y))))))))))
 
 (define-variable scroll-step
   "*The number of lines to try scrolling a window by when point moves out.
 If that fails to bring point back on screen, point is centered instead.
 If this is zero, point is always centered after it moves off screen."
-  0)
-
-(define-variable-value-validity-test (ref-variable-object scroll-step)
+  0
   (lambda (scroll-step)
     (and (fix:fixnum? scroll-step)
         (fix:>= scroll-step 0))))
@@ -872,13 +868,10 @@ If this is zero, point is always centered after it moves off screen."
 (define-variable cursor-centering-point
   "The distance from the top of the window at which to center the point.
 This number is a percentage, where 0 is the window's top and 100 the bottom."
-  50)
-
-(define-variable-value-validity-test
-  (ref-variable-object cursor-centering-point)
-  (lambda (value)
-    (and (real? value)
-        (<= 0 value 100))))
+  50
+  (lambda (cursor-centering-point)
+    (and (real? cursor-centering-point)
+        (<= 0 cursor-centering-point 100))))
 \f
 ;;;; Line Inferiors
 
@@ -969,7 +962,7 @@ This number is a percentage, where 0 is the window's top and 100 the bottom."
       (begin
        (set-mark-position! (%window-current-start-mark window)
                            (mark-position (%window-start-line-mark window)))
-       (set-mark-index! (%window-current-end-mark window) end))
+       (set-mark-index-integrable! (%window-current-end-mark window) end))
       (begin
        (%set-window-current-start-mark!
         window

diff --git a/v7/src/edwin/bufwiu.scm b/v7/src/edwin/bufwiu.scm
index fafe8a40f1d336c47e98040050b3bbda1406a786..9fe916d59f5f967c6c7ea3f83cb3b50e5e94222a 100644 (file)
--- a/v7/src/edwin/bufwiu.scm
+++ b/v7/src/edwin/bufwiu.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwiu.scm,v 1.13 1990/11/02 03:23:02 cph Rel $
+;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwiu.scm,v 1.14 1991/03/15 23:48:02 cph Exp $
 ;;;
 ;;;    Copyright (c) 1986, 1989, 1990 Massachusetts Institute of Technology
 ;;;
@@ -151,7 +151,14 @@
                 (fix:< end (%window-start-index window))))
        (begin
          (clear-start-mark! window)
-         (window-needs-redisplay! window)))))
+         (window-needs-redisplay! window)))
+    (let ((point (%window-point-index window)))
+      (cond ((fix:< point start)
+            (%set-window-point-index! window start)
+            (%set-window-point-moved?! window 'SINCE-START-SET))
+           ((fix:< end point)
+            (%set-window-point-index! window end)
+            (%set-window-point-moved?! window 'SINCE-START-SET))))))
 \f
 ;;;; Update
 
@@ -164,14 +171,12 @@
       (let ((start (%window-current-start-index window))
            (end (%window-current-end-index window)))
        (cond ((and (%window-start-clip-mark window)
-                   (let ((start-clip (%window-start-clip-index window))
-                         (end-clip (%window-end-clip-index window)))
-                     (or (and (fix:<= start start-clip)
-                              (fix:<= (%window-group-start-index window)
-                                      end))
-                         (and (fix:<= end-clip end)
-                              (fix:<= start
-                                      (%window-group-end-index window))))))
+                   (or (not (and (fix:<= (%window-group-start-index window) start)
+                                 (fix:<= end (%window-group-end-index window))))
+                       (fix:< (%window-group-start-index window)
+                              (%window-start-clip-index window))
+                       (fix:< (%window-end-clip-index window)
+                              (%window-group-end-index window))))
               (preserve-nothing! window))
              ((%window-start-changes-mark window)
               (let ((start-changes