Re: [Emacs-diffs] master 134ba45: Allow two mouse functions to work with Rectangle Mark mode

[martin rudalics]

> I don't understand enough of the "dragged into itself" test to know what
> should be done here.  I think part of the issue is that for rectangular
> regions, the "insert-for-yank" will actually not just insert, so we
> can't just test "is insertion-point inside region-bounds?" (which could
> be easily implemented in a generic way).  But at the same time, why
> should we disallow dragging the rectangle to a place that overlaps its
> original location?

AFAICT, the drag into itself case is different for contiguous and
non-contiguous regions.  For the former we want to avoid changing
anything because we would clutter undo with actions that remove and
re-add the same portion of text at the same position.  For rectangles
we allow to move the rectangle such that the buffer regions spanned by
the beginning of the first and the end of the last region of original
and dragged rectangle may overlap while the individual regions do not
overlap.

martin