bug#13592: 24.2.92; C-s prompts with "Multi I-search:" today

[Drew Adams]

>  . Why is it a good idea to show this Multi thing at the very
>    beginning of the search, when there's no evidence whatsoever that
>    the search is in danger of crossing into the next file in the
>    series?  It's confusing to see this, because _I_ didn't ask for
>    multi-file or multibuffer isearch.  It took me by surprise and
>    forced me to go looking for the reason (tried in other versions of
>    Emacs and in other buffers, before it dawned on me that it is
>    something specific to add-log mode).  You want to be nice to me?
>    fine: then show this to me when I type C-s that will cross into the
>    next file, but not before that.  _Then_ I might appreciate the
>    service.  But when I type my first C-s, please give me just what I
>    asked for.
> 
>  . This should at least be documented in the manual.  When I saw this
>    prompt, I tried to figure out what it meant (did someone really
>    think that "Multi" explains it all?), but it seems not to be
>    mentioned anywhere in the docs.  Even the NEWS entry for Emacs
>    23.1, which does say that isearch is automatically multi-file in
>    ChangeLog files, doesn't mention this prompt.  I needed to wade
>    through isearch.el to find what it meant, only to find out that the
>    facility used to trigger it -- multi-search-next-buffer-function --
>    is not documented in the Elisp manual, either, which sounds weird
>    if we consider such features useful in other modes.  Is this a
>    secret of some sorts?

+1 on both accounts.  (And well put.)