[O] org-save-outline-visibility and isearch

[Milan Zamazal]

After using org-save-outline-visibility the invisible parts of the
buffer become invisible to isearch.  I have to do something like calling
org-global-cycle to restore the buffer to its original state and allow
searching in its invisible parts again.

The problem seems to be in the functions org-outline-overlay-data and
org-set-outline-overlay-data.  They save and restore just `invisible'
overlays.  They should do the same with `isearch-open-invisible'
overlays.  Or perhaps org-set-outline-overlay-data could simply use
outline-flag-region?

What do you think?