Re: wrong cursor position reported when window margins are wide

[Eli Zaretskii <eliz@gnu.org>]

> From: Joost Kremers <joostkremers@fastmail.fm>
> Date: Tue, 28 Feb 2017 15:01:22 +0100
> 
> I recently had a bug report for a package[1] I maintain, which 
> seems to be a bug in Emacs itself. The user that reported the bug 
> uses Fcitx[2], an X-Window based input framework for Chinese 
> (probably other Asian languages as well, but I have no expertise 
> in that area). Another user reported the same problem for another 
> such input framework, ibus[3].
> 
> Basically, these input methods consist of a small box (GUI window) 
> that follows the text cursor. They rely on the underlying program 
> (i.e., in this case Emacs) to report the cursor position in order 
> to position the input box correctly.
> 
> It seems that when the window margins of an Emacs window are 
> non-nil, the cursor position is reported incorrectly, resulting in 
> the input box being displayed in the wrong place.
> 
> The original bug report is here:
> 
> <https://github.com/joostkremers/visual-fill-column/issues/25#issuecomment-281844388>
> 
> There are screen shots that illustrate the problem. (Scroll down a 
> bit for screen shots with `emacs -Q'.)

Sorry, I couldn't understand what is meant by "cursor position
reporting".  Could you clarify, and perhaps show an example of how
that reported position changes when a window has display margins?

Thanks.