diff --git a/hgext/convert/git.py b/hgext/convert/git.py
--- a/hgext/convert/git.py
+++ b/hgext/convert/git.py
@@ -82,6 +82,7 @@ class convert_git(converter_source):
         tzs, tzh, tzm = tz[-5:-4] + "1", tz[-4:-2], tz[-2:]
         tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))
         date = tm + " " + str(tz)
+        author = author or unknown
 
         c = commit(parents=parents, date=date, author=author, desc=message)
         return c
diff --git a/mercurial/archival.py b/mercurial/archival.py
--- a/mercurial/archival.py
+++ b/mercurial/archival.py
@@ -133,7 +133,6 @@ class zipit:
     def addfile(self, name, mode, data):
         i = zipfile.ZipInfo(self.prefix + name, self.date_time)
         i.compress_type = self.z.compression
-        i.flag_bits = 0x08
         # unzip will not honor unix file modes unless file creator is
         # set to unix (id 3).
         i.create_system = 3