topic: setup 'topic' value for working ctx
The way amend work in core change in e8a7c1a0565a. The intermediate commit
disappear and we can no longer rely on it to carry the topic value to amend. To
fix this, we ensure the current topic value can be retrieved through the
`workingctx.extra()` value. Since there is no way to carry a "missing" key
information in a way that survives and "dict.update" call. We also has to
introduce hacking behavior about a special empty value for topic.
Topic Extension
================
This packages also provides the ``topic`` experiment in an independent
extension. It implements a new experimental concept to provide lightweight
feature branches for the mutable parts of the history. The experiments is still
at an early stage and have significant usability and performance issues when
enabled.
How to Install
==============
The ``topic`` extension is included into the ``evolve` package, so the same instruction apply.
Using Pip
---------
You can install the latest version using pip::
$ pip install --user hg-evolve
Then just enable it in you hgrc::
$ hg config --edit # adds the two line below:
[extensions]
topic =
From Source
-----------
To install a local version from source::
$ hg clone https://www.mercurial-scm.org/repo/evolve/
$ cd evolve
$ make install-home
Enable
------
The topic extensions is included in the evolve package. See the install instruction for evolve.
Then enable it in you configuration::
$ hg config --edit # adds the two line below:
[extensions]
topic =
Documentation
-------------
* See 'hg help -e topic' for a generic help.
* See 'hg help topics' and 'hg help stack' for help on specific commands.
* See the 'tests/test-topic-tutorial.t' file for a quick tutorial.