From 7ec057458135eed0dd08e2de4089e4814d71e440 Mon Sep 17 00:00:00 2001
From: Juri Linkov <juri@linkov.net>
Date: Sun, 15 Aug 2021 19:18:05 +0300
Subject: [PATCH] * lisp/simple.el (shift-select-mode): Add new choice
 'permanent' (bug#50038).

(handle-shift-selection): Handle new choice 'permanent'.
---
 etc/NEWS       |  6 ++++++
 lisp/simple.el | 16 ++++++++++++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 09ace73f5d9..c2b53e47050 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -263,6 +263,12 @@ This works in text buffers and over images.  Typing a numeric prefix arg
 (e.g. 'M-5') before starting horizontal scrolling changes its step value.
 The value is saved in the user option 'mouse-wheel-scroll-amount-horizontal'.
 
+---
+** New choice 'permanent' for 'shift-select-mode'.
+When the mark was activated by shifted motion keys,
+non-shifted motion keys don't deactivate the mark
+after customizing 'shift-select-mode' to 'permanent'.
+
 ---
 ** The default value of 'frame-title-format' and 'icon-title-format' has changed.
 These variables are used to display the title bar of visible frames
diff --git a/lisp/simple.el b/lisp/simple.el
index 1661346b375..7da315e8692 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -6660,9 +6660,16 @@ is temporarily turned on.  Furthermore, the mark will be deactivated
 by any subsequent point motion key that was not shift-translated, or
 by any action that normally deactivates the mark in Transient Mark mode.
 
+When the value is `permanent', the mark will be deactivated by any
+action which normally does that, but not by motion keys that were
+not shift-translated.
+
 See `this-command-keys-shift-translated' for the meaning of
 shift-translation."
-  :type 'boolean
+  :type '(choice (const :tag "Off" nil)
+                 (const :tag "Permanent" permanent)
+                 (other :tag "On" t))
+  :version "28.1"
   :group 'editing-basics)
 
 (defun handle-shift-selection ()
@@ -6680,7 +6687,12 @@ translation.
 Otherwise, if the region has been activated temporarily,
 deactivate it, and restore the variable `transient-mark-mode' to
 its earlier value."
-  (cond ((and shift-select-mode this-command-keys-shift-translated)
+  (cond ((and (eq shift-select-mode 'permanent)
+              this-command-keys-shift-translated)
+         (unless mark-active
+           (push-mark nil nil t)))
+        ((and shift-select-mode
+              this-command-keys-shift-translated)
          (unless (and mark-active
 		      (eq (car-safe transient-mark-mode) 'only))
 	   (setq-local transient-mark-mode
-- 
2.39.2