Handle EmptyFile Exception.

See jonashaag#297

This at least fixes viewing of a repository with some broken objects in it; viewing the objects themselves will still result in exceptions, but that requires case-by-case work.

klaus/repo.py

@@ -3,7 +3,7 @@
 import stat
 import subprocess
 
-from dulwich.objects import S_ISGITLINK
+from dulwich.objects import S_ISGITLINK, EmptyFileException
 from dulwich.object_store import tree_lookup_path
 from dulwich.objects import Blob
 from dulwich.errors import NotTreeError
@@ -161,7 +161,7 @@ def get_ref_names_ordered_by_last_commit(self, prefix, exclude=None):
         def get_commit_time(refname):
             try:
                 obj = self[refs[refname]]
-            except InaccessibleRef:
+            except (InaccessibleRef, EmptyFileException):
                 # Default to 0, i.e. sorting refs that point at non-existant
                 # objects last.
                 return 0