Merge node common to several branches

Noticing a pattern:

  hg branch b
  ... edit b ...
  ... test ...
  hg merge -r default
  ... test ...
  hg ci -m 'merged default into b'
  hg update -r default
  hg merge -r b
  ... diff -r default -r b
  ... test ...
  hg ci -m 'merged from branch b into default (after already merged default into branch b, i.e. identical node in both default and branch b'

This seems suboptimal.

It seems to me that instead of creating the same node, wrt content, on two branches, in this case default and b, we could create it once.  And link it in to both branches.

Key: must remember that the node is on both branches, so that afterwards can continue working separately.

I.e. could have updated to the merge node M but be on the default branch.  Or on the b branch.  (Or possibly both?)


It may be common to end a branch at such a merge node.  Perhaps commn enough to be the default.  But not univeral.