Add branch_name_in_commit plugin

README.md

@@ -145,8 +145,9 @@ class Filter:
         #Or don't pass, if you want to do some init code here
 ```
 
-Beyond the boilerplate initialization, you can see the one of the
-defined filter methods in the [dos2unix](./plugins/dos2unix) plugin.
+Beyond the boilerplate initialization, you can see the two different
+defined filter methods in the [dos2unix](./plugins/dos2unix) and
+[branch_name_in_commit](./plugins/branch_name_in_commit) plugins.
 
 ```
 commit_data = {'branch': branch, 'parents': parents, 'author': author, 'desc': desc}

plugins/branch_name_in_commit/README.md

@@ -0,0 +1,10 @@
+## Branch Name in Commit Message
+
+Mercurial has a much stronger notion of branches than Git,
+and some parties may not wish to lose the branch information
+during the migration to Git. You can use this plugin to either
+prepend or append the branch name from the mercurial
+commit into the commit message in Git.
+
+To use the plugin, add
+`--plugin branch_name_in_commit=(start|end)`.

plugins/branch_name_in_commit/__init__.py

@@ -0,0 +1,14 @@
+def build_filter(args):
+    return Filter(args)
+
+class Filter:
+    def __init__(self, args):
+        if not args in ['start','end']:
+            raise Exception('Cannot have branch name anywhere but start and end')
+        self.pos = args
+
+    def commit_message_filter(self,commit_data):
+        if self.pos == 'start':
+            commit_data['desc'] = commit_data['branch'] + '\n' + commit_data['desc']
+        if self.pos == 'end':
+            commit_data['desc'] = commit_data['desc'] + '\n' + commit_data['branch']