Retrieve empty hash block.

Fixes #1607

diff --git a/pithos/backends/lib/hashfiler/blocker.py b/pithos/backends/lib/hashfiler/blocker.py
index 817376b..49aa20c 100644 (file)
--- a/pithos/backends/lib/hashfiler/blocker.py
+++ b/pithos/backends/lib/hashfiler/blocker.py
@@ -115,6 +115,9 @@ class Blocker(object):
         block = None
 
         for h in hashes:
+            if h == self.emptyhash:
+                append('')
+                continue
             with self._get_rear_block(h, 0) as rbl:
                 if not rbl:
                     break