Hi Stefan,

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

>>> Removing just the text property seems cleaner.
>> I guess this solution, though nice, is tricky to implement.
>
> Why do you think so?

I looked at the way isearch does the temporary opening of overlays,
and it looks complex to add another mechanism to temporarily ignore
the 'invisible text property.  At least I don't know how to do this.

Also, I tried a preliminary patches (attached) which I find quite
convenient and seems to do what I expected first when setting
(setq search-invisible t): turning on visible-mode.

The patch is not fully tested and incomplete, as query-replace is
not handled, but that's a start.

Let me know what you think.

Thanks,

-- 
 Bastien