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.
#!/usr/bin/env python
#
# An example FastCGI script for use with flup, edit as necessary
# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"
# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")
# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb
from flup.server.fcgi import WSGIServer
application = hgweb(config)
WSGIServer(application).run()