comparison mercurial/filemerge.py @ 22028:3d0572ab3b4a

merge: add an internal:merge3 tool

This variant gives access to a feature already present in ``internal:merge``:
displaying merge base content.

In the basic merge (calling ``hg merge``) case, including more context to the
merge markers is an interesting addition.

But this extra information is the only viable option in case conflict from
grafting (, rebase, etc…).

When grafting ``source`` on ``destination``, the parent of ``source`` is
used as the ``base``. When all three changesets add content in the same
location, the marker for ``source`` will contains both ``base`` and ``source``
content. Without the content of base exposed, there is no way for the user
to discriminate content coming from ``base`` and content commit from ``source``.

Practical example (all addition are in the same place):

* ``destination`` adds ``Dest-Content``
* ``base``        adds ``Base-Content``
* ``source``      adds ``Src-Content``

Grafting ``source`` on ``destination`` will produce the following conflict:

  <<<<<<< destination
  Dest-Content
  =======
  Base-Content
  Src-Content
  >>>>>>> source

This that case there is no way to distinct ``base`` from ``source``. As a result
content from ``base`` are likely to slip in the resolution result.

However, adding the base make the situation very clear:

  <<<<<<< destination
  Dest-Content
  ||||||| base
  Base-Content
  ======= base
  Base-Content
  Src-Content
  >>>>>>> source

Once the base is added, the addition from the grafted changeset is made clear.
User can compare the content from ``base`` and ``source`` to make an enlightened
decision during merge resolution.

22027:b98e5c7afc70

        r = simplemerge.simplemerge(ui, a, b, c, label=labels)
        return True, r
    return False, 0

@internaltool('tagmerge', True,
              _("automatic tag merging of %s failed! "
                "(use 'hg resolve --tool internal:merge' or another merge "
                "tool of your choice)\n"))
def _itagmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

22028:3d0572ab3b4a

        r = simplemerge.simplemerge(ui, a, b, c, label=labels)
        return True, r
    return False, 0

@internaltool('merge3', True,
              _("merging %s incomplete! "
                "(edit conflicts, then use 'hg resolve --mark')\n"))
def _imerge3(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
    """
    Uses the internal non-interactive simple merge algorithm for merging
    files. It will fail if there are any conflicts and leave markers in
    the partially merged file. Marker will have three sections, one from each
    side of the merge and one for the base content."""
    if not labels:
        labels = _defaultconflictlabels
    if len(labels) < 3:
        labels.append('base')
    return _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels)

@internaltool('tagmerge', True,
              _("automatic tag merging of %s failed! "
                "(use 'hg resolve --tool internal:merge' or another merge "
                "tool of your choice)\n"))
def _itagmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):