From d75794fd5c168fb76406b88e231d8749160f934a Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= Date: Thu, 31 Oct 2019 10:31:27 +0100 Subject: [PATCH] Inhibit undo-in-region for mouse-drag-region (bug#37700) 'mouse-drag-region' leaves the region active around the dragged text, so a straight undo did not revert the entire operation. To remedy this, inhibit undo-in-region when the last command was mouse-drag-region. (Method suggested by Stefan Monnier.) * lisp/mouse.el (undo-drag-region): Set the undo-inhibit-region property. * lisp/simple.el (undo): Inhibit undo-in-region if the last command had the undo-inhibit-region property set. * doc/lispref/symbols.texi (Standard Properties): * doc/lispref/text.texi (Undo): Document undo-inhibit-region. * etc/NEWS: Announce the property. --- doc/lispref/symbols.texi | 5 +++++ doc/lispref/text.texi | 6 ++++++ etc/NEWS | 6 ++++++ lisp/mouse.el | 6 ++++++ lisp/simple.el | 7 ++++++- 5 files changed, 29 insertions(+), 1 deletion(-) diff --git a/doc/lispref/symbols.texi b/doc/lispref/symbols.texi index 5d71fb39a25..936bda9b36e 100644 --- a/doc/lispref/symbols.texi +++ b/doc/lispref/symbols.texi @@ -590,6 +590,11 @@ ignore a call whose value is unused. If the property's value is calls. In addition to byte compiler optimizations, this property is also used for determining function safety (@pxref{Function Safety}). +@item undo-inhibit-region +If non-@code{nil}, the named function prevents the @code{undo} operation +from being restricted to the active region, if @code{undo} is invoked +immediately after the function. @xref{Undo}. + @item variable-documentation If non-@code{nil}, this specifies the named variable's documentation string. This is set automatically by @code{defvar} and related diff --git a/doc/lispref/text.texi b/doc/lispref/text.texi index ac444f6afeb..9bc6213f3ac 100644 --- a/doc/lispref/text.texi +++ b/doc/lispref/text.texi @@ -1451,6 +1451,12 @@ continuing to undo. This function does not bind @code{undo-in-progress}. @end defun +Some commands leave the region active after execution in such a way that +it interferes with selective undo of that command. To make @code{undo} +ignore the active region when invoked immediately after such a command, +set the property @code{undo-inhibit-region} of the command's function +symbol to a non-nil value. @xref{Standard Properties}. + @node Maintaining Undo @section Maintaining Undo Lists diff --git a/etc/NEWS b/etc/NEWS index ee73d2414bd..7a76d90ed53 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -3102,6 +3102,12 @@ in other packages are now obsolete aliases of 'xor'. Setting this on the first character of a help string disables conversions via 'substitute-command-keys'. ++++ +** 'undo' can be made to ignore the active region for a command +by setting 'undo-inhibit-region' symbol property of that command to +non-nil. This is used by 'mouse-drag-region' to make the effect +easier to undo immediately afterwards. + * Changes in Emacs 27.1 on Non-Free Operating Systems diff --git a/lisp/mouse.el b/lisp/mouse.el index 76fec507e71..4a351f7be25 100644 --- a/lisp/mouse.el +++ b/lisp/mouse.el @@ -1104,6 +1104,12 @@ is dragged over to." (run-hooks 'mouse-leave-buffer-hook) (mouse-drag-track start-event))) +;; Inhibit the region-confinement when undoing mouse-drag-region +;; immediately after the command. Otherwise, the selection left +;; active around the dragged text would prevent an undo of the whole +;; operation. +(put 'mouse-drag-region 'undo-inhibit-region t) + (defun mouse-posn-property (pos property) "Look for a property at click position. POS may be either a buffer position or a click position like diff --git a/lisp/simple.el b/lisp/simple.el index 29e195bca6c..10aecd651f3 100644 --- a/lisp/simple.el +++ b/lisp/simple.el @@ -2508,6 +2508,10 @@ as an argument limits undo to changes within the current region." (base-buffer (or (buffer-base-buffer) (current-buffer))) (recent-save (with-current-buffer base-buffer (recent-auto-save-p))) + ;; Allow certain commands to inhibit an immediately following + ;; undo-in-region. + (inhibit-region (and (symbolp last-command) + (get last-command 'undo-inhibit-region))) message) ;; If we get an error in undo-start, ;; the next command should not be a "consecutive undo". @@ -2525,7 +2529,8 @@ as an argument limits undo to changes within the current region." ;; it shows nothing else happened in between. (gethash list undo-equiv-table)))) (setq undo-in-region - (or (region-active-p) (and arg (not (numberp arg))))) + (and (or (region-active-p) (and arg (not (numberp arg)))) + (not inhibit-region))) (if undo-in-region (undo-start (region-beginning) (region-end)) (undo-start)) -- 2.39.5