Context menu related fixes (bug#64980)

* etc/PROBLEMS: Suggest how to keep context menus open on Lucid.

* lisp/mouse.el (context-menu-mode-map): Bind [mouse-3] to
'ignore' instead of 'nil' to not fallback to the default binding.
(mouse--drag-start-event): Remove unused variable.
(mouse-undouble-last-event): Remove unused function.

2 files changed, 10 insertions, 24 deletions

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 5da83fefeb1..be023b3d5ce 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -2012,6 +2012,15 @@ Very long popup menus cannot be shown in their entirety, and don't have
 a scroll bar to scroll them vertically.  Lucid does not support this
 feature.  A workaround is to use other toolkits (GTK, LessTif, etc.).
 
+*** In Emacs built with Lucid cannot keep context menus open.
+
+After enabling context-menu-mode, when the menu is opened by
+<down-mouse-3>, it closes right away when the right mouse button
+is released.  It's possible to keep the context menu open
+after releasing the mouse button by disabling XInput 2 support:
+
+  ./configure --with-x-toolkit=lucid --without-xinput2
+
 *** Emacs running under X Window System does not handle mouse clicks.
 *** 'emacs -geometry 80x20' finds a file named '80x20'.
 
diff --git a/lisp/mouse.el b/lisp/mouse.el
index 907a4883230..b8d46d8dbed 100644
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -687,7 +687,7 @@ Some context functions add menu items below the separator."
 
 (defvar context-menu-mode-map
   (let ((map (make-sparse-keymap)))
-    (define-key map [mouse-3] nil)
+    (define-key map [mouse-3] #'ignore)
     (define-key map [down-mouse-3] context-menu-entry)
     (define-key map [menu] #'context-menu-open)
     (if (featurep 'w32)
@@ -1520,8 +1520,6 @@ point determined by `mouse-select-region-move-to-beginning'."
        (eq mouse-last-region-end (region-end))
        (eq mouse-last-region-tick (buffer-modified-tick))))
 
-(defvar mouse--drag-start-event nil)
-
 (defun mouse-set-region (click)
   "Set the region to the text dragged over, and copy to kill ring.
 This should be bound to a mouse drag event.
@@ -2064,27 +2062,6 @@ If MODE is 2 then do the same for lines."
     (if (numberp (posn-point posn))
         (push-mark (posn-point posn) t t))))
 
-(defun mouse-undouble-last-event (events)
-  (let* ((index (1- (length events)))
-         (last (nthcdr index events))
-         (event (car last))
-         (basic (event-basic-type event))
-         (old-modifiers (event-modifiers event))
-         (modifiers (delq 'double (delq 'triple (copy-sequence old-modifiers))))
-         (new
-          (if (consp event)
-              ;; Use reverse, not nreverse, since event-modifiers
-              ;; does not copy the list it returns.
-              (cons (event-convert-list (reverse (cons basic modifiers)))
-                    (cdr event))
-            event)))
-    (setcar last new)
-    (if (and (not (equal modifiers old-modifiers))
-             (key-binding (apply #'vector events)))
-        t
-      (setcar last event)
-      nil)))
-
 ;; Momentarily show where the mark is, if highlighting doesn't show it.
 
 (defun mouse-set-mark (click)