How does mercurial determine that a branch is inactive?

Question

What determines if a branch is inactive? Is there a specific time period the client uses?

We have a lot of branches that are inactive. Would it be worth our while to close them?

The documentation does not seem to specify how an inactive branch is determined: https://www.mercurial-scm.org/wiki/Branch

Answer 1

From hg help branches (quoted on the page you link to):

A branch is considered active if it contains unmerged heads.

Inversely then, a branch is inactive if it has no unmerged heads.