bug#58158: 29.0.50; [overlay] Interval tree iteration considered harmful

[Eli Zaretskii]

> Date: Sat, 8 Oct 2022 21:50:39 +0300
> Cc: gerd.moellmann@gmail.com, 58158@debbugs.gnu.org, monnier@iro.umontreal.ca
> From: Dmitry Gutov <dgutov@yandex.ru>
> 
> > Btw, what am I doing wrong below?
> > 
> >   emacs -Q
> >   C-x C-f src/character.h RET
> >   M-x visit-tags-table RET RET
> >   M-. char_string RET
> >   r whatever RET
> > 
> > Unexpected result: "No suitable matches here".  Huh? what did I miss?
> 
> We can't replace over "find definition" matches: they are more abstract 
> and don't contain the necessary information to perform the replacement 
> (such as the length of a match, for instance).
> 
> And such xrefs might navigate you to the beginning of the line, for 
> example, rather than to the beginning of the name.
> 
> But that makes sense, doesn't it? If replacing over "find definitions" 
> results worked fine, in the end you would get a codebase where all 
> declarations of a method 'foo' got renamed, but all callsites of it 
> remain unchanged. That couldn't have been your intention, could it?
> 
> The error message could use some improvement, I suppose, but I'm not 
> sure how to make it better.

I tried to improve the situation, both in the error message, the doc
string, and the manual.