[ Ralf, I have a question I'd like to ask you. Please see below. ]

Hi Gustavo, sorry to be very late to respond.

>>>>> Gustavo Barros <gusbrs.2016@gmail.com> writes:
> When both TeX-fold-mode and outline-minor-mode are used together, if
> the outline is folded, the usual unfolding of candidates of isearch
> does not work, that is, temporary unfolding of the region where the
> current candidate is does not happen. The unfolding of the region of
> the selected candidate also does not happen.

I can observe the behavior you described. It seems that this issue is
caused because `TeX-fold-mode' sets `search-invisible' to t locally. It
doesn't occur if that value is changed from t to `open', as the attached
patch does. The value `open' is default value of `search-invisible'.

However, I'm not yet sure whether to apply this patch, since it seems
the current code deliberately chooses the value t, disliking the default
value `open'.

Ralf, do you remember why you chose t, not the default value of `open',
for `search-invisible' when you wrote `TeX-fold-mode'?

Best regards,
Ikumi Keita