Revert changeset c67920d78248.
It breaks 'hg merge && hg up -c REV' when files exist only in one of the
manifests, making hg throw a traceback like:
1:016807e6fdaf
0:eb43f19ff115
016807e6fdaf tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
eb43f19ff115
eb43f19ff115+
reverting file1
? file1.orig
eb43f19ff115
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip
? file1.orig
016807e6fdaf tip
? file1.orig
016807e6fdaf tip
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip