comparison tests/test-merge-criss-cross.t @ 28011:8abd9f785030

merge: add file ancestor linknode to mergestate

During a merge, each file has a current commitnode+filenode, an other
commitnode+filenode, and an ancestor commitnode+filenode. The ancestor
commitnode is not stored though, and we rely on the ability for the filectx() to
look up the commitnode by using the filenode's linkrev. In alternative backends
(like remotefilelog), linkrevs may have restriction that prevent arbitrary
linkrev look up given a filenode.

This patch accounts for that by storing the ancestor commitnode in
the merge state so that it is available later at resolve time.

This results in some test changes because the ancestor commitnode we're using at
resolve time changes slightly. Before, we used the linkrev commit, which is the
earliest commit that introduced that particular filenode (which may not be the
latest common ancestor of the commits being merged). Now we use the latest
common ancestor of the merged commits as the commitnode. This is fine though,
because that commit contains the same filenode as the linkrev'd commit.

28010:eb22def9db3b

   f1: remote is newer -> g
  getting f1
   f2: versions differ -> m (premerge)
  picked tool ':dump' for f2 (binary False symlink False changedelete False)
  merging f2
  my f2@3b08d01b0ab5+ other f2@adfe50279922 ancestor f2@40494bf2444c
   f2: versions differ -> m (merge)
  picked tool ':dump' for f2 (binary False symlink False changedelete False)
  my f2@3b08d01b0ab5+ other f2@adfe50279922 ancestor f2@40494bf2444c
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ head *

28011:8abd9f785030

   f1: remote is newer -> g
  getting f1
   f2: versions differ -> m (premerge)
  picked tool ':dump' for f2 (binary False symlink False changedelete False)
  merging f2
  my f2@3b08d01b0ab5+ other f2@adfe50279922 ancestor f2@0f6b37dbe527
   f2: versions differ -> m (merge)
  picked tool ':dump' for f2 (binary False symlink False changedelete False)
  my f2@3b08d01b0ab5+ other f2@adfe50279922 ancestor f2@0f6b37dbe527
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ head *