Package: emacs;
Reported by: Juri Linkov <juri <at> linkov.net>
Date: Thu, 20 Sep 2018 23:57:01 UTC
Severity: minor
Found in version 27.0.50
Done: Juri Linkov <juri <at> linkov.net>
Bug is archived. No further changes may be made.
Message #362 received at 32790 <at> debbugs.gnu.org (full text, mbox):
From: Juri Linkov <juri <at> linkov.net> To: martin rudalics <rudalics <at> gmx.at> Cc: Eli Zaretskii <eliz <at> gnu.org>, 32790 <at> debbugs.gnu.org Subject: Re: bug#32790: 27.0.50; point jumps unexpectedly after delete-window Date: Mon, 03 Dec 2018 02:45:35 +0200
[Message part 1 (text/plain, inline)]
>>> These ones stupefied me when I tried to study your patch yesterday. >>> When 'switch-to-buffer-obey-display-actions' is non-nil you do not >>> reset 'force-same-window' so you can get an error when this is t and >>> you're either in the minibuffer or the window is strongly dedicated. >>> Right? >> >> I don't understand how 'force-same-window' can be non-nil if there is >> a condition "unless switch-to-buffer-obey-display-actions" in the >> interactive spec. But if some code calls 'switch-to-buffer' >> non-interactively with non-nil 'force-same-window', should it >> signal an error when 'pop-to-buffer-same-window' displays the buffer >> in another window? > > The non-interactive case is the one I had in mind. I think we mean to > say that FORCE-SAME-WINDOW has no impact in that case and We already added this to the docstring two patches ago. This was the part of that change: If optional argument FORCE-SAME-WINDOW is non-nil, the buffer must be displayed in the selected window when called non-interactively; if that is impossible, signal an error rather -than calling `pop-to-buffer'. +than calling `pop-to-buffer'. It has no effect when the option +`switch-to-buffer-obey-display-actions' is non-nil. > 'switch-to-buffer' should not signal an error when the window is > dedicated or the minibuffer window but try to automatically display > the buffer in a window of its choice instead. Do you think this is right?
[switch-to-buffer-obey-display-actions.3.patch (text/x-diff, inline)]
diff --git a/lisp/window.el b/lisp/window.el
index 2634955a75..8313f71b54 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -7743,8 +7743,10 @@ switch-to-buffer-preserve-window-point
position in the selected window.
This variable is ignored if the buffer is already displayed in
-the selected window or never appeared in it before, or if
-`switch-to-buffer' calls `pop-to-buffer' to display the buffer."
+the selected window, or never appeared in it before, or if
+`switch-to-buffer' calls `pop-to-buffer' to display the buffer,
+or non-nil `switch-to-buffer-obey-display-actions' displays it
+in another window."
:type '(choice
(const :tag "Never" nil)
(const :tag "If already displayed elsewhere" already-displayed)
@@ -7779,6 +7781,16 @@ switch-to-buffer-in-dedicated-window
:group 'windows
:version "25.1")
+(defcustom switch-to-buffer-obey-display-actions nil
+ "If non-nil, `switch-to-buffer' runs `pop-to-buffer-same-window' instead.
+This means that when switching the buffer it respects display actions
+specified by `display-buffer-overriding-action', `display-buffer-alist'
+and other display related variables. So `switch-to-buffer' will display
+the buffer in the window specified by the rules from these variables."
+ :type 'boolean
+ :group 'windows
+ :version "27.1")
+
(defun switch-to-buffer (buffer-or-name &optional norecord force-same-window)
"Display buffer BUFFER-OR-NAME in the selected window.
@@ -7811,59 +7823,83 @@ switch-to-buffer
If optional argument FORCE-SAME-WINDOW is non-nil, the buffer
must be displayed in the selected window when called
non-interactively; if that is impossible, signal an error rather
-than calling `pop-to-buffer'.
+than calling `pop-to-buffer'. It has no effect when the option
+`switch-to-buffer-obey-display-actions' is non-nil.
The option `switch-to-buffer-preserve-window-point' can be used
to make the buffer appear at its last position in the selected
window.
+If the option `switch-to-buffer-obey-display-actions' is non-nil,
+run the function `pop-to-buffer-same-window' instead.
+This may display the buffer in another window as specified by
+`display-buffer-overriding-action', `display-buffer-alist' and
+other display related variables. If this results in displaying
+the buffer in the selected window, window start and point are adjusted
+as prescribed by the option `switch-to-buffer-preserve-window-point'.
+Otherwise, these are left alone.
+
Return the buffer switched to."
(interactive
(let ((force-same-window
- (cond
- ((window-minibuffer-p) nil)
- ((not (eq (window-dedicated-p) t)) 'force-same-window)
- ((pcase switch-to-buffer-in-dedicated-window
- ('nil (user-error
- "Cannot switch buffers in a dedicated window"))
- ('prompt
- (if (y-or-n-p
- (format "Window is dedicated to %s; undedicate it"
- (window-buffer)))
- (progn
- (set-window-dedicated-p nil nil)
- 'force-same-window)
- (user-error
- "Cannot switch buffers in a dedicated window")))
- ('pop nil)
- (_ (set-window-dedicated-p nil nil) 'force-same-window))))))
+ (unless switch-to-buffer-obey-display-actions
+ (cond
+ ((window-minibuffer-p) nil)
+ ((not (eq (window-dedicated-p) t)) 'force-same-window)
+ ((pcase switch-to-buffer-in-dedicated-window
+ ('nil (user-error
+ "Cannot switch buffers in a dedicated window"))
+ ('prompt
+ (if (y-or-n-p
+ (format "Window is dedicated to %s; undedicate it"
+ (window-buffer)))
+ (progn
+ (set-window-dedicated-p nil nil)
+ 'force-same-window)
+ (user-error
+ "Cannot switch buffers in a dedicated window")))
+ ('pop nil)
+ (_ (set-window-dedicated-p nil nil) 'force-same-window)))))))
(list (read-buffer-to-switch "Switch to buffer: ") nil force-same-window)))
- (let ((buffer (window-normalize-buffer-to-switch-to buffer-or-name)))
+ (let ((buffer (window-normalize-buffer-to-switch-to buffer-or-name))
+ (set-window-start-and-point (not switch-to-buffer-obey-display-actions)))
(cond
;; Don't call set-window-buffer if it's not needed since it
;; might signal an error (e.g. if the window is dedicated).
- ((eq buffer (window-buffer)))
- ((window-minibuffer-p)
+ ((and (eq buffer (window-buffer))
+ ;; pop-to-buffer-same-window might decide to display
+ ;; the same buffer in another window
+ (not switch-to-buffer-obey-display-actions)))
+ ((and (window-minibuffer-p)
+ (not switch-to-buffer-obey-display-actions))
(if force-same-window
(user-error "Cannot switch buffers in minibuffer window")
(pop-to-buffer buffer norecord)))
- ((eq (window-dedicated-p) t)
+ ((and (eq (window-dedicated-p) t)
+ (not switch-to-buffer-obey-display-actions))
(if force-same-window
(user-error "Cannot switch buffers in a dedicated window")
(pop-to-buffer buffer norecord)))
(t
- (let* ((entry (assq buffer (window-prev-buffers)))
- (displayed (and (eq switch-to-buffer-preserve-window-point
- 'already-displayed)
- (get-buffer-window buffer 0))))
- (set-window-buffer nil buffer)
- (when (and entry
- (or (eq switch-to-buffer-preserve-window-point t)
- displayed))
- ;; Try to restore start and point of buffer in the selected
- ;; window (Bug#4041).
- (set-window-start (selected-window) (nth 1 entry) t)
- (set-window-point nil (nth 2 entry))))))
+ (when switch-to-buffer-obey-display-actions
+ (let ((selected-window (selected-window)))
+ (pop-to-buffer-same-window buffer norecord)
+ (when (eq (selected-window) selected-window)
+ (setq set-window-start-and-point t))))
+
+ (when set-window-start-and-point
+ (let* ((entry (assq buffer (window-prev-buffers)))
+ (displayed (and (eq switch-to-buffer-preserve-window-point
+ 'already-displayed)
+ (get-buffer-window buffer 0))))
+ (set-window-buffer nil buffer)
+ (when (and entry
+ (or (eq switch-to-buffer-preserve-window-point t)
+ displayed))
+ ;; Try to restore start and point of buffer in the selected
+ ;; window (Bug#4041).
+ (set-window-start (selected-window) (nth 1 entry) t)
+ (set-window-point nil (nth 2 entry)))))))
(unless norecord
(select-window (selected-window)))
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