[Emacs-diffs] emacs/lisp follow.el

[Chong Yidong]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Chong Yidong <cyd>      08/12/30 16:21:21

Modified files:
        lisp           : follow.el 

Log message:
        (follow-select-if-visible): Improve the check for the
        last line of the window.
        (follow-post-command-hook): Perform redisplay in more circumstances,
        to avoid getting point stuck on partially visible lines.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/lisp/follow.el?cvsroot=emacs&r1=1.52&r2=1.53

Patches:
Index: follow.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/follow.el,v
retrieving revision 1.52
retrieving revision 1.53
diff -u -b -r1.52 -r1.53
--- follow.el   30 Dec 2008 15:09:35 -0000      1.52
+++ follow.el   30 Dec 2008 16:21:20 -0000      1.53
@@ -1033,21 +1033,27 @@
 (defun follow-select-if-visible (dest win-start-end)
   "Select and return a window, if DEST is visible in it.
 Return the selected window."
-  (let (win)
+  (let (win win-end)
     (while (and (not win) win-start-end)
       ;; Don't select a window that was just moved. This makes it
       ;; possible to later select the last window after a `end-of-buffer'
       ;; command.
       (when (follow-pos-visible dest (caar win-start-end) win-start-end)
-       (setq win (caar win-start-end))
+       (setq win (caar win-start-end)
+             win-end (car (cddr (car win-start-end))))
        (select-window win))
       (setq win-start-end (cdr win-start-end)))
     ;; The last line of the window may be partially visible; if so,
     ;; and if point is visible in the next window, select the next
     ;; window instead.
-    (and (/= dest (point-max))
+    (and win
+        (/= dest (point-max))
         win-start-end
         (follow-pos-visible dest (caar win-start-end) win-start-end)
+        (save-excursion
+          (goto-char dest)
+          (vertical-motion 1 win)
+          (>= (point) win-end))
         (setq win (caar win-start-end))
         (select-window win))
     win))
@@ -1373,13 +1379,13 @@
                 ((and visible aligned)
                  (follow-debug-message "same"))
                 ;; Pick a position in any window.  If the display is
-                ;; ok, this will pick the `correct' window.  If the
-                ;; display is wierd (e.g., after a delete at the
-                ;; beginning of the window) do this anyway.
+                ;; ok, this will pick the `correct' window.
                 ((follow-select-if-visible dest win-start-end)
                  (follow-debug-message "visible")
-                 (setq visible t)
-                 (goto-char dest))
+                 (goto-char dest)
+                 ;; We have to perform redisplay, since scrolling is
+                 ;; needed in case the line is partially visible.
+                 (setq visible nil))
                 ;; Not visible anywhere else, lets pick this one.
                 ;; (Is this case used?)
                 (visible
@@ -1411,16 +1417,10 @@
                (let ((p (window-point win)))
                  (set-window-start win (window-start win) nil)
                  (set-window-point win p))))
-           (unless (or visible
-                       ;; Use the UPDATE argument of window-end
-                       ;; instead of calling follow-pos-visible
-                       ;; (which may be inaccurate for partially
-                       ;; visible lines).
-                       (and (>= dest (window-start))
-                            (< dest (window-end nil t))))
-             ;; If point is not visible in the selected window,
-             ;; perform a redisplay; this causes scrolling.
-             (sit-for 0)
+           (unless visible
+             ;; If point may not be visible in the selected window,
+             ;; perform a redisplay; this ensures scrolling.
+             (redisplay)
              (setq selected-window-up-to-date t)
              (follow-avoid-tail-recenter)
              (setq win-start-end (follow-windows-start-end windows))