bug#24030: 25.0.95; mouse-drag-region regression

[Stefan Monnier]

> that creates a buffer-local binding for it.  That is why select-window
> gives deactivate-mark a non-nil value: select-window makes the
> window's buffer the current one, which assigns buffer-local values to
> all of it variables, including deactivate-mark.  Then this
> buffer-local value is being examined by mouse-drag-region.

Indeed, this is a problem here because of have a "stale" setting of
deactivate-mark.

Maybe something like the patch below will do?

Another option is to make the deactivate-mark function reset
deactivate-mark to nil (which would seem to make a lot of sense in
itself) and then to call deactivate-mark at that point or to move the
earlier deactivate-mark to after mouse-set-point.

Of course, maybe there should be a more thorough handling of stale
deactivate-mark settings.  IOW change all places that set
deactivate-mark to non-nil so they also record the affected buffer and
then change the command loop so that it calls deactivate-mark in all
those buffers where deactivate-mark was set as non-nil.


        Stefan


diff --git a/lisp/mouse.el b/lisp/mouse.el
index 27f2acb..6175d77 100644
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -811,6 +811,7 @@ mouse-drag-track
          ;; window, now let's jump to the place of the event, where things
          ;; are happening.
          (_ (mouse-set-point start-event))
+         (_ (kill-local-variable 'deactivate-mark))
          (echo-keystrokes 0)
         (start-posn (event-start start-event))
         (start-point (posn-point start-posn))