Find the latest merge point of two branches

Question

Having two branches, how can I find the latest revision(s) where the two branches were merged? Is there a standard Mercurial command to do that?

This is the same as ques

Answer 1

Just for the posterity this is not right in the case the left branch has not been merged with the right branch, but the left branch has lately been merged into right.

The correct solution is:

last(parents((ancestors('{left_branch}') and branch('{left_branch}') and merge())) and branch({right_branch}))