During concurrent editing actions on the same subtree of aPage, users sometimes experience a corruption of that tree.

By running./manage.py cms fix-tree this can be fixed, but since we are approaching ~30k pages this operation takes a while and might cause other race conditions while its running.

I therefore would like to propose the following change to that management command:

It should accept an optional parameter to restrict the repair mechanism to a given subtree of a page. The question is, if that parameter should be a URL or the Page-ID itself?