Improve treatment of aborted touch events in Speedbar and elsewhere

* lisp/dframe.el (dframe-popup-kludge): Mark as a
mouse-1-menu-command.

* lisp/touch-screen.el (touch-screen-handle-point-up): New
argument CANCELED.  Implement specific responses to cancellation
for each tool state.
(touch-screen-handle-touch): Adjust to match.

lisp/dframe.el

@@ -684,6 +684,8 @@ Must be bound to event E."
     (sit-for 0)
     (popup-menu (mouse-menu-major-mode-map) e)))
 
+(put 'dframe-popup-kludge 'mouse-1-menu-command t)
+
 ;;; Interactive user functions for the mouse
 ;;
 (defun dframe-mouse-event-p (event)

lisp/touch-screen.el

@@ -1254,17 +1254,20 @@ response to the minibuffer being closed."
         (cancel-timer minibuffer-on-screen-keyboard-timer)
         (setq minibuffer-on-screen-keyboard-timer nil)))))
 
-(defun touch-screen-handle-point-up (point prefix)
+(defun touch-screen-handle-point-up (point prefix canceled)
   "Notice that POINT has been removed from the screen.
 POINT should be the point currently tracked as
 `touch-screen-current-tool'.
 PREFIX should be a virtual function key used to look up key
 bindings.
+CANCELED should indicate whether the touch point was removed by
+window-system intervention rather than user action.
 
 If an ancillary touch point is being observed, transfer touch
 information from `touch-screen-aux-tool' to
-`touch-screen-current-tool' and set it to nil, thereby resuming
-gesture recognition with that tool replacing the tool removed.
+`touch-screen-current-tool' and set the former to nil, thereby
+resuming gesture recognition with that tool replacing the tool
+removed.
 
 Otherwise:
 
@@ -1315,6 +1318,9 @@ is not read-only."
                  ;; hasn't been moved, translate the sequence into a
                  ;; regular mouse click.
                  (eq what 'restart-drag))
+             ;; Don't attempt to execute commands bound to mouse events
+             ;; if the touch sequence has been canceled.
+             (unless canceled
                (when (windowp (posn-window posn))
                  (setq point (posn-point posn)
                        window (posn-window posn))
@@ -1380,9 +1386,12 @@ is not read-only."
                            ;; or some such, return it as a key sequence.
                            (throw 'input-event event)))
                      ;; If not, return the event.
-                   (throw 'input-event event)))))
+                     (throw 'input-event event))))))
             ((eq what 'mouse-drag)
              ;; Generate a corresponding `mouse-1' event.
+             ;; Alternatively, quit if the touch sequence was canceled.
+             (if canceled
+                 (keyboard-quit)
                (let* ((new-window (posn-window posn))
                       (new-point (posn-point posn))
                       (old-posn (nth 4 touch-screen-current-tool))
@@ -1416,17 +1425,19 @@ is not read-only."
                               (list 'mouse-1 posn)
                             ;; ... otherwise, generate a drag-mouse-1
                             ;; event.
-                          (list 'drag-mouse-1 old-posn posn))))))
+                            (list 'drag-mouse-1 old-posn posn)))))))
             ((eq what 'mouse-1-menu)
              ;; Generate a `down-mouse-1' event at the position the tap
-             ;; took place.
+             ;; took place, unless the touch sequence was canceled.
+             (unless canceled
                (throw 'input-event
                       (list 'down-mouse-1
-                          (nth 4 touch-screen-current-tool))))
+                            (nth 4 touch-screen-current-tool)))))
             ((or (eq what 'drag)
                  ;; Merely initiating a drag is sufficient to select a
                  ;; word if word selection is enabled.
                  (eq what 'held))
+             (unless canceled
                ;; Display the on screen keyboard if the region is now
                ;; active.  Check this within the window where the tool
                ;; was first place.
@@ -1444,7 +1455,7 @@ is not read-only."
                        (add-hook 'window-selection-change-functions
                                  #'touch-screen-window-selection-changed)
                        (frame-toggle-on-screen-keyboard (selected-frame)
-                                                      nil))))))))))
+                                                        nil)))))))))))
 
 (defun touch-screen-handle-touch (event prefix &optional interactive)
   "Handle a single touch EVENT, and perform associated actions.
@@ -1684,16 +1695,12 @@ functions undertaking event management themselves to call
           (setq touch-screen-current-timer nil))
         (let ((old-aux-tool touch-screen-aux-tool))
           (unwind-protect
-              ;; Don't perform any actions associated with releasing the
-              ;; tool if the touch sequence was intercepted by another
-              ;; program.
-              (if (caddr event)
-                  (setq touch-screen-current-tool nil)
-                (touch-screen-handle-point-up (cadr event) prefix))
+              (touch-screen-handle-point-up (cadr event) prefix
+                                            (caddr event))
             ;; If an ancillary tool is present the function call above
-            ;; will merely transfer information from it into the current
-            ;; tool list, thereby rendering it the new current tool,
-            ;; until such time as it too is released.
+            ;; will simply transfer information from it into the current
+            ;; tool list, rendering the new current tool, until such
+            ;; time as it too is released.
             (when (not (and old-aux-tool (not touch-screen-aux-tool)))
               ;; Make sure the tool list is cleared even if
               ;; `touch-screen-handle-point-up' throws.