mergestate: add a constructor that sets up a clean merge state Eventually, we'll move the read call out of the constructor. This will: - avoid unnecessary reads when we're going to nuke the merge state anyway - avoid raising an exception if there's an unsupported merge record 'clean' seems like a good name for it because I wanted to avoid anything with the word 'new' in it, and 'reset' is more an action performed on a merge state than a way to get a new merge state. Thanks to Martin von Zweigbergk for feedback about naming this.

--- a/mercurial/merge.py	Tue Nov 17 14:11:52 2015 -0800
+++ b/mercurial/merge.py	Tue Nov 17 17:00:54 2015 -0800
@@ -75,6 +75,14 @@
     statepathv1 = 'merge/state'
     statepathv2 = 'merge/state2'
 
+    @staticmethod
+    def clean(repo, node=None, other=None):
+        """Initialize a brand new merge state, removing any existing state on
+        disk."""
+        ms = mergestate(repo)
+        ms.reset(node, other)
+        return ms
+
     def __init__(self, repo):
         self._repo = repo
         self._dirty = False