diff --git a/mercurial/shelve.py b/mercurial/shelve.py
--- a/mercurial/shelve.py
+++ b/mercurial/shelve.py
@@ -413,6 +413,36 @@
         cmdutil.exportfile(repo, [node], fp, opts=mdiff.diffopts(git=True),
                            match=match)
 
+def _encodemergerecords(records):
+    """Encode mergestate records to store in changeset extras.
+    Takes list of tuples as input and returns str.
+    """
+    items = [
+        '%s\033%s' % (rtype, record)
+        for rtype, record in sorted(records)
+    ]
+    return "\n".join(items)
+
+def _decodemergerecords(data):
+    """Decode mergestate record from changeset extras to return
+    a list of tuples.
+    """
+    records = []
+    for l in data.split('\n'):
+        rtype, record = l.split('\033')
+        records.append((rtype, record))
+    return records
+
+def _storeunresolvedmerge(ui, repo, name=None, extra=None):
+    """Store the mergestate information in changeset extra
+
+    This will clear the mergestate and also stores the mergestate
+    information for later restoration.
+    """
+    ms = merge.mergestate.read(repo)
+    extra['mergerecords'] = _encodemergerecords(ms._readrecords())
+    ms.reset()
+
 def _includeunknownfiles(repo, pats, opts, extra):
     s = repo.status(match=scmutil.match(repo[None], pats, opts),
                     unknown=True)