bug#64696: 30.0.50; indent-to inherits preceding text properties, including 'invisible

[Stefan Monnier]

> ⛔ Warning (emacs): Test #2:: ’word’ is inside folded heading (hidden using 
> overlays).
> ⛔ Warning (emacs): Moved point after first ’word’
> ⛔ Warning (emacs): 1:: current-column = 4
>
> Test #2 is unexpected - we are inside invisible region, but
> current-column reports as if everything were visible.

Side note: `current-column` treats invisible text differently
depending on whether it's replaced by ellipses or not.

This was done so that reindenting a region or a sexp doesn't go haywire
when part of the region is currently hidden by code folding.

I now think that relying on "ellipses or not" was not a great idea
(there are ellipses which `current-column` should count as the width of
the ellipsis rather than the width of the hidden text, e.g. when
ellipses are used to truncate cells in a table).


        Stefan