Add dos2unix plugin

README.md

@@ -145,6 +145,8 @@ 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.
 
 ```
 commit_data = {'branch': branch, 'parents': parents, 'author': author, 'desc': desc}

plugins/dos2unix/README.md

@@ -0,0 +1,9 @@
+## Dos2unix filter
+
+This plugin converts CRLF line ending to LF in text files in the repo.
+It is recommended that you have a .gitattributes file that maintains
+the usage of LF endings going forward, for after you have converted your
+repository.
+
+To use the plugin, add
+`--plugin dos2unix`.

plugins/dos2unix/__init__.py

@@ -0,0 +1,11 @@
+def build_filter(args):
+    return Filter(args)
+
+class Filter():
+    def __init__(self, args):
+        pass
+
+    def file_data_filter(self,file_data):
+        file_ctx = file_data['file_ctx']
+        if not file_ctx.isbinary():
+            file_data['data'] = file_data['data'].replace('\r\n', '\n')