bug#57433: Emacs no longer moves point into visible port of the buffer

[Gerd Möllmann]

Paul Pogonyshev <pogonyshev@gmail.com> writes:

> Git commit 233c91d32a. Has been broken at least for a few days: my previous 
> build also exhibited this.
>
> No idea how to create a short test in Elisp.
>
> From user point of view: open a Magit buffer in a directory with at least two 
> locally modified and uncommitted files. The buffer shows sth. like
> this:
>
> ...
> Staged changes (N)
> modified   file1
> modified   file2
> ...
>
> Move the point with C-n to the line with `file2'. Press TAB. Magit section 
> for the file is not opened. Use `M-x describe-char'. From the resulting
> buffer you can say that the point is actually on an invisible char '@', i.e. 
> start of (hidden) diff for the first file.
>
> It may be necessary to restart Emacs if you have used Magit in this directory 
> previously.
>
> This used to work fine (i.e. point was never on an invisible character) both 
> in Emacs 28 and earlier snapshots of `master'.
>
> Paul

I can reproduce this.  Bisecting.