bug#29002: it.first_visible_x is erroneously 0 while horizontal scrolling.

[Eli Zaretskii]

> Date:  Sun, 29 Oct 2017 13:12:15 -0700
> From:  Keith David Bershatsky <esq@lawlist.com>
> Cc:  29002@debbugs.gnu.org
> 
> It appears to me that (scroll-right 1) is kind of a temporary form of 
> horizontal scrolling, which automatically cancels as to non-current lines in 
> a vareity of situations when keyboard input is received.  Plain old 
> scroll-right without the optional distance argument is semi-permanent, and 
> non-current lines do not automatically return to a non-scrolled state.

Yes, it's temporary.  For a permanent hscroll, you need to invoke
scroll-left/right with its second argument non-nil (which happens
automatically in interactive invocation).

Does the hscroll get reset after moving cursor if you type "M-x"?