On 2017-05-30 18:23, npostavs@users.sourceforge.net wrote:
> Clément Pit--Claudel <clement.pitclaudel@live.com> writes:
> 
>> Setting comment-continue to " " breaks the logic of
>> uncomment-region-default, causing it to get into an infinite loop
>> (repeatedly matching an empty string at the same location).
>> uncomment-region-default is used by comment-line (C-x C-;).
> 
> Can you give a full recipe?

Sure thing:

emacs -Q --eval '(setq comment-continue "  ")' --eval '(save-excursion (insert ";; AAA\n"))' --eval '(comment-line 1)'

Clément.