bug#43587: move-to-column behaves differently when text has invisible property

[Eli Zaretskii]

> From: Christoph Arenz <tiga.arenz@web.de>
> Date: Tue, 29 Sep 2020 17:56:45 +0200
> 
> Digging deeper into bug 43587, it seems to be related to move-to-column 
> behaving slightly different when the
> text in a line has the invisible property set.
> 
> Here is how to recreate. According to the documentation for move-to-column, I 
> would not expect any
> difference between the two lines:
> 
> > Optional second argument FORCE non-nil means if COLUMN is in the middle of 
> > a tab character, change
> it to spaces.
> 
> For the first line, the tab has not been changed to spaces...
> 
> Am I overlooking something?

Yes, move-to-column skips invisible text.