Bug: headline folding broken by whitespace

[Daniele Nicolodi]

Hello,

i saw a few reports of bugs related to folding and unfolding of
headlines recently, but I think this is not a duplicate.

I just noticed that with the latest release (Org mode version 9.4
(9.4-27-g47bf60-elpa @ /Users/daniele/.emacs.d/elpa/org-20201026/)
unfolding of headlines is broken by whitespace. In particular with a
buffer with this content:

* Foo
** Bar
   bar bar bar+49 1520 7178926


* Baz

where the line before "* Baz" contains a single whitespace character,
the headline "* Foo" can be folded but cannot be unfolded. Removing the
whitespace while the headline is folded fixes the problem.

Cheers,
Dan