[Emacs-diffs] master 8d09cb2: Handle scroll-error-top-bottom in follow.el and view.el (bug#21893)

[Juri Linkov]

branch: master
commit 8d09cb21f8ad4c3d3197dadfcc38fe925da558d0
Author: Juri Linkov <address@hidden>
Commit: Juri Linkov <address@hidden>

    Handle scroll-error-top-bottom in follow.el and view.el (bug#21893)
    
    * lisp/follow.el (follow-scroll-up-arg, follow-scroll-up-window):
    Use scroll-up-command instead of scroll-up.
    (follow-scroll-down-arg, follow-scroll-down-window):
    Use scroll-down-command instead of scroll-down.
    (follow-scroll-up, follow-scroll-down): Handle scroll-error-top-bottom.
    
    * lisp/view.el (view-scroll-lines): Use scroll-down-command
    instead of scroll-down and scroll-up-command instead of scroll-up.
    (view-really-at-end): Handle scroll-error-top-bottom.
---
 lisp/follow.el | 22 ++++++++++++++--------
 lisp/view.el   |  7 ++++---
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/lisp/follow.el b/lisp/follow.el
index acc2b26..faac879 100644
--- a/lisp/follow.el
+++ b/lisp/follow.el
@@ -557,7 +557,7 @@ This is an internal function for `follow-scroll-up' and
   (let ((opoint (point))  (owin (selected-window)))
     (while
         ;; If we are too near EOB, try scrolling the previous window.
-        (condition-case nil (progn (scroll-up arg) nil)
+        (condition-case nil (progn (scroll-up-command arg) nil)
           (end-of-buffer
            (condition-case nil (progn (follow-previous-window) t)
              (error
@@ -576,7 +576,7 @@ If ARG is nil, scroll the size of the current window.
 This is an internal function for `follow-scroll-down' and
 `follow-scroll-down-window'."
   (let ((opoint (point)))
-    (scroll-down arg)
+    (scroll-down-command arg)
     (unless (and scroll-preserve-screen-position
                  (get this-command 'scroll-command))
       (goto-char opoint))
@@ -596,7 +596,7 @@ Negative ARG means scroll downward.
 Works like `scroll-up' when not in Follow mode."
   (interactive "P")
   (cond ((not follow-mode)
-        (scroll-up arg))
+        (scroll-up-command arg))
        ((eq arg '-)
         (follow-scroll-down-window))
        (t (follow-scroll-up-arg arg))))
@@ -616,7 +616,7 @@ Negative ARG means scroll upward.
 Works like `scroll-down' when not in Follow mode."
   (interactive "P")
   (cond ((not follow-mode)
-        (scroll-down arg))
+        (scroll-down-command arg))
        ((eq arg '-)
         (follow-scroll-up-window))
        (t (follow-scroll-down-arg arg))))
@@ -635,13 +635,16 @@ Negative ARG means scroll downward.
 Works like `scroll-up' when not in Follow mode."
   (interactive "P")
   (cond ((not follow-mode)
-        (scroll-up arg))
+        (scroll-up-command arg))
        (arg (follow-scroll-up-arg arg))
         (t
         (let* ((windows (follow-all-followers))
                (end (window-end (car (reverse windows)))))
           (if (eq end (point-max))
-              (signal 'end-of-buffer nil)
+              (if (or (null scroll-error-top-bottom)
+                      (eobp))
+                  (signal 'end-of-buffer nil)
+                (goto-char (point-max)))
             (select-window (car windows))
             ;; `window-end' might return nil.
             (if end
@@ -663,14 +666,17 @@ Negative ARG means scroll upward.
 Works like `scroll-down' when not in Follow mode."
   (interactive "P")
   (cond ((not follow-mode)
-        (scroll-down arg))
+        (scroll-down-command arg))
        (arg (follow-scroll-down-arg arg))
         (t
         (let* ((windows (follow-all-followers))
                (win (car (reverse windows)))
                (start (window-start (car windows))))
           (if (eq start (point-min))
-              (signal 'beginning-of-buffer nil)
+              (if (or (null scroll-error-top-bottom)
+                      (bobp))
+                  (signal 'beginning-of-buffer nil)
+                (goto-char (point-min)))
             (select-window win)
             (goto-char start)
             (vertical-motion (- (- (window-height win)
diff --git a/lisp/view.el b/lisp/view.el
index a765be0..e4489b3 100644
--- a/lisp/view.el
+++ b/lisp/view.el
@@ -743,18 +743,19 @@ invocations return to earlier marks."
     (setq backward (not backward) lines (- lines)))
   (when (and maxdefault lines (> lines (view-window-size)))
     (setq lines nil))
-  (cond (backward (scroll-down lines))
+  (cond (backward (scroll-down-command lines))
        ((view-really-at-end)
         (if view-scroll-auto-exit
             (View-quit)
           (ding)
           (view-end-message)))
-       (t (scroll-up lines)
+       (t (scroll-up-command lines)
           (if (view-really-at-end) (view-end-message)))))
 
 (defun view-really-at-end ()
   ;; Return true if buffer end visible.  Maybe revert buffer and test.
-  (and (pos-visible-in-window-p (point-max))
+  (and (or (null scroll-error-top-bottom) (eobp))
+       (pos-visible-in-window-p (point-max))
        (let ((buf (current-buffer))
             (bufname (buffer-name))
             (file (buffer-file-name)))