https://bz.mercurial-scm.org/522 In the merge below, the file "foo" has the same contents in both parents, but if we look at the file-level history, we'll notice that the version in p1 is an ancestor of the version in p2. This test makes sure that we'll use the version from p2 in the manifest of the merge revision. $ hg init $ echo foo > foo $ hg ci -qAm 'add foo' $ echo bar >> foo $ hg ci -m 'change foo' $ hg backout -r tip -m 'backout changed foo' reverting foo changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e $ hg up -C 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ touch bar $ hg ci -qAm 'add bar' $ hg merge --debug searching for copies back to rev 1 unmatched files in local: bar resolving manifests branchmerge: True, force: False, partial: False ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee foo: remote is newer -> g getting foo 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg debugstate | grep foo m 0 -2 unset foo $ hg st -A foo M foo $ hg ci -m 'merge' $ hg manifest --debug | grep foo c6fc755d7e68f49f880599da29f15add41f42f5a 644 foo $ hg debugindex foo rev linkrev nodeid p1 p2 0 0 2ed2a3912a0b 000000000000 000000000000 1 1 6f4310b00b9a 2ed2a3912a0b 000000000000 2 2 c6fc755d7e68 6f4310b00b9a 000000000000