bug#2421: 23.0.90; python-mode: Indent commands behavior

[martin rudalics]

>     mr> Isn't that shift behavior something that should be done via
>     mr> rectangles?
>
> Do you mean by the user?  No, this would require marking the region on
> exact characters rather than lines, i.e. it would be less comfortable

You're right that rect.el doesn't have suitable code for highlighting
and dragging rectangles.  cua-rect.el has two functions for shifting
rectangles, but I don't know whether they could be used here.

> and would make the operation more visual than logical.

That was my intention.  I don't know whether `python-shift-left' and
`python-shift-right' are of any use without a prefix argument.  With a
prefix argument, they are simple wrappers for `indent-rigidly'.  And
`indent-rigidly' is a purely visual operation.  That is, if indenting
part of a program changes the semantics of the program, it's the user
who's responsible, without any "logical" support from `python-mode'.

But since I never use these functions you shouldn't take my remarks too
seriously.  Maybe you could propose a patch to provide the behavior you
like.  In any case, it might be better to use `use-region-p' instead of
`mark-active' to be more consistent with Emacs 23.

martin