Fix bug w. 0 file syncing

kamaki/clients/pithos/__init__.py

@@ -66,9 +66,11 @@ def _range_up(start, end, max_value, a_range):
     :returns: (str) a range string cut-off for the start-end range
         an empty response means this window is out of range
     """
-    assert start >= 0, '_range_up was called with start < 0'
-    assert end >= start, '_range_up was called with end < start'
-    assert end <= max_value, '_range_up was called with max_value < end'
+    assert start >= 0, '_range_up called w. start(%s) < 0' % start
+    assert end >= start, '_range_up called w. end(%s) < start(%s)' % (
+        end, start)
+    assert end <= max_value, '_range_up called w. max_value(%s) < end(%s)' % (
+        max_value, end)
     if not a_range:
         return '%s-%s' % (start, end)
     selected = []
@@ -729,6 +731,7 @@ class PithosClient(PithosRestClient):
             self._cb_next(len(blockids) - len(unsaved))
             if unsaved:
                 key = unsaved[0]
+                if key:
                     self._watch_thread_limit(flying.values())
                     self._thread2file(
                         flying, blockid_dict, local_file, offset,
@@ -739,7 +742,8 @@ class PithosClient(PithosRestClient):
                     if not data_range:
                         self._cb_next()
                         continue
-                restargs['async_headers'] = {'Range': 'bytes=%s' % data_range}
+                    restargs[
+                        'async_headers'] = {'Range': 'bytes=%s' % data_range}
                     flying[key] = self._get_block_async(obj, **restargs)
                     blockid_dict[key] = unsaved