--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -59,7 +59,10 @@ class mercurial_sink(converter_sink):
pass
def putcommit(self, files, parents, commit):
- seen = {}
+ if not files:
+ return hex(self.repo.changelog.tip())
+
+ seen = {hex(nullid): 1}
pl = []
for p in parents:
if p not in seen: