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hg-fast-export.(sh|py) - mercurial to git converter using git-fast-import

=========================================================================

Legal

-----

Most hg-* scripts are licensed under the [MIT license]

(http://www.opensource.org/licenses/mit-license.php) and were written

by Rocco Rutte <pdmef@gmx.net> with hints and help from the git list and

\#mercurial on freenode. hg-reset.py is licensed under GPLv2 since it

copies some code from the mercurial sources.

The current maintainer is Frej Drejhammar <frej.drejhammar@gmail.com>.

Usage

-----

Using hg-fast-export is quite simple for a mercurial repository <repo>:

```

mkdir repo-git # or whatever

cd repo-git

git init

hg-fast-export.sh -r <repo>

```

Please note that hg-fast-export does not automatically check out the

newly imported repository. You probably want to follow up the import

with a `git checkout`-command.

Incremental imports to track hg repos is supported, too.

Using hg-reset it is quite simple within a git repository that is

hg-fast-export'ed from mercurial:

```

hg-reset.sh -R <revision>

```

will give hints on which branches need adjustment for starting over

again.

When a mercurial repository does not use utf-8 for encoding author

strings and commit messages the `-e <encoding>` command line option

can be used to force fast-export to convert incoming meta data from

<encoding> to utf-8. This encoding option is also applied to file names.

In some locales Mercurial uses different encodings for commit messages

and file names. In that case, you can use `--fe <encoding>` command line

option which overrides the -e option for file names.

As mercurial appears to be much less picky about the syntax of the

author information than git, an author mapping file can be given to

hg-fast-export to fix up malformed author strings. The file is

specified using the -A option. The file should contain lines of the

form `FromAuthor=ToAuthor`. The example authors.map below will

translate `User <garbage<user@example.com>` to `User <user@example.com>`.

```

-- Start of authors.map --

User <garbage<user@example.com>=User <user@example.com>

-- End of authors.map --

```

Tag and Branch Naming

---------------------

As Git and Mercurial have differ in what is a valid branch and tag

name the -B and -T options allow a mapping file to be specified to

rename branches and tags (respectively). The syntax of the mapping

file is the same as for the author mapping.

Notes/Limitations

-----------------

hg-fast-export supports multiple branches but only named branches with

exactly one head each. Otherwise commits to the tip of these heads

within the branch will get flattened into merge commits.

As each git-fast-import run creates a new pack file, it may be

required to repack the repository quite often for incremental imports

(especially when importing a small number of changesets per

incremental import).

The way the hg API and remote access protocol is designed it is not

possible to use hg-fast-export on remote repositories

(http/ssh). First clone the repository, then convert it.

Design

------

hg-fast-export.py was designed in a way that doesn't require a 2-pass

mechanism or any prior repository analysis: if just feeds what it

finds into git-fast-import. This also implies that it heavily relies

on strictly linear ordering of changesets from hg, i.e. its

append-only storage model so that changesets hg-fast-export already

saw never get modified.

Submitting Patches

------------------

Please use the issue-tracker at github

https://github.com/frej/fast-export to report bugs and submit

patches.