bug#16546: C-s vs. whitespace highlighting

[martin rudalics]

>> Yes, good idea.  I also think search for two whitespace chars in a row
>> should temporary toggle `search-whitespace-regexp' to nil.
>
> IMO, that behavior would make sense only when the whitespace chars are
> entered interactively (i.e. typed on the keyboard), because if the
> search string comes from another place (copy&paste, grabbed from the
> buffer, ...), I don't think it would be a good idea to temporarily set
> `search-whitespace-regexp' to nil.  And BTW, that reasoning applies
> equally to case-fold-search.
>
> IOW, if I copy some text "foo<any-whitespace>bar" from one place and
> then go to Emacs and do "C-s C-y", I definitely want a "lax" search
> wrt whitespace.
>
> At least, that behavior should be configurable, IMO.

Searching for two or more whitespace characters without any surrounding
non-whitespace characters should bind `search-whitespace-regexp' to nil.
This would trivially take care of Dan's original problem.  And it should
go into Emacs 24.4 because Dan's scenario reveals a very obvious bug.

martin