Re: mouse.el patch for region tracking

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Recently I found that Emacs 22 breaks a simple usage of mouse-drag- 
>> region for defining regions by mouse drag.  When transient-mark-mode  
>> is set, mouse-drag-region under Emacs 21 would let you define a  
>> region by dragging, and when the drag is released, it completes (at  
>> which point you can operate on the region).

> I can still do that with an Emacs built from CVS yesterday.

How?  The mouse-drag-region function doesn't end when you release the mouse
but only after the next event (this is because it's waiting to see if the
next event is in mouse-region-delete-keys).  That makes it unusable in other
contexts (when you try to do something similar to what XEmacs's mouse-track
function does).

In Emacs-21, there was a bug which was that when transient-mark-mode was
enabled, mouse-region-delete-keys wasn't obeyed (and the function returned
immediately upon the release of the mouse button).  JD unknowingly relied on
this bug to get the behavior he needs.

My vote would be to kill mouse-region-delete-keys, but it seems that Richard
insists on this functionality so it looks like JD's patch is a good and safe
way to recover the old feature which is used by several third party
elisp packages.


        Stefan