According to the http://www.jetbrains.com/idea/features/editions_comparison_matrix.html the community edition has mercurial support, but does it really?
There is nothing related to the mercurial in the UI and in the settings.
The PyCharm help (http://www.jetbrains.com/pycharm/webhelp/?Setting_Up_a__Local_Mercurial_Repository) has some information on the mercurial usage, but from the description it should just work. And the Idea documentation (http://www.jetbrains.com/idea/webhelp/vcss.html) has no mention of mercurial at all.
So, does Idea (for Java) support mercurial or doesn't?