Re: isearch highlighting with zero-length match

[Juri Linkov <juri@jurta.org>]

YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp> writes:
> Could someone please take care of the following issue that I posted to
> emacs-pretest-bug in January?  Carbon Emacs no longer hangs with this,
> but waste of CPU time would occur in any platform.

I looked at this patch.  It really fixes all mentioned problems and I think
it should be installed.

I was surprised that `isearch-lazy-highlight-update' is called even
for empty search strings.  This means that every time users type C-s
it iterates over all characters in the window.  This may be not noticeable
on fast machines, but still is useless.  If the search string is "",
it is guaranteed that nothing is going to be highlighted.  I think
`isearch-lazy-highlight-new-loop' should prevent lazy highlighting for
empty search strings (I mean if isearch-string is "", not other cases
with zero-length matches where there is no such guarantee).

-- 
Juri Linkov
http://www.jurta.org/emacs/