bug#28658: 27.0.50; [PATCH] double/triple clicking in xterm-mouse-mode doesn't respect mouse position

[Alex <agrambot@gmail.com>]

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1. emacs -Q -nw
2. M-x xterm-mouse-mode RET
3. Click once, then quickly move the cursor to a different word and click again.
4. Notice that the 2nd click was registered as a double click even
though the cursor moved.
5. Click once, and quickly perform step 3 again. Notice that the 3rd
click was registered as a triple click even though the cursor moved.

I've attached a patch that fixes this behaviour. It would be nice if it
worked with pixel positions rather than character positions, but I'm not
sure how to do that in a terminal Emacs.


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From 77590f427ba962f5efc3f07d2e4dcadb4ec1237d Mon Sep 17 00:00:00 2001
From: Alexander Gramiak <agrambot@gmail.com>
Date: Sat, 30 Sep 2017 15:47:56 -0600
Subject: [PATCH] Increase xterm click count only with unchanged point

* lisp/xt-mouse.el (xterm-mouse-event): Save the last click's position
and check it against the current click's position.
---
 lisp/xt-mouse.el | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lisp/xt-mouse.el b/lisp/xt-mouse.el
index 772a72d5c5..dc202e78f6 100644
--- a/lisp/xt-mouse.el
+++ b/lisp/xt-mouse.el
@@ -278,6 +278,8 @@ xterm-mouse-event
                (last-name (symbol-name last-type))
                (last-time (nth 1 last-click))
                (click-count (nth 2 last-click))
+               (last-x (nth 3 last-click))
+               (last-y (nth 4 last-click))
                (this-time (float-time))
                (name (symbol-name type)))
           (cond
@@ -290,12 +292,14 @@ xterm-mouse-event
               (xterm-mouse--set-click-count event click-count)))
            ((not last-time) nil)
            ((and (> double-click-time (* 1000 (- this-time last-time)))
+                 (eq x last-x)
+                 (eq y last-y)
                  (equal last-name (replace-match "" t t name)))
             (setq click-count (1+ click-count))
             (xterm-mouse--set-click-count event click-count))
            (t (setq click-count 1)))
           (set-terminal-parameter nil 'xterm-mouse-last-click
-                                  (list type this-time click-count)))
+                                  (list type this-time click-count x y)))
 
         (set-terminal-parameter nil 'xterm-mouse-x x)
         (set-terminal-parameter nil 'xterm-mouse-y y)
-- 
2.14.1