bug#46316: 27.1; wrong horizontal scroll with truncate-lines value t

[Eli Zaretskii]

> Cc: 46316@debbugs.gnu.org
> From: ynyaaa@gmail.com
> Date: Mon, 08 Feb 2021 03:54:32 +0900
> 
> I only want auto-hscroll-mode to scroll buffer automatically.

It does, when you give it enough information that it should.  When
your input focus is in another window (the mini-window in the case of
C-s), I think it would be strange for Emacs to auto-scroll some other
window.

> If a searched string is not displayed in the window, I might think the
> searched string does not exist in the buffer.

The searched string _is_ displayed, when you first find it.

> If an image is hidden, I might think the image is a solid color same as
> the emacs background color.

Just move the cursor and you will see it.

Sorry, I see no problem here, certainly not something that would
justify complicated triggers for redisplaying a window.