Fix non-string arguments to metadata_check

src/filter.py

@@ -236,8 +236,14 @@ class Filter(object):
         metadata = self._client_dest.stream_get_metadata(self.dest.path)
         if not self.force_metadata:
             for key in data:
-                wanted = str(data[key])
+                wanted = data[key]
+                if not isinstance(wanted, basestring):
+                    wanted = str(wanted)
                 val = metadata.get(key, wanted)
+                # Force UTF-8 encoding for comparison and display
+                wanted = wanted.encode('utf-8')
+                val = val.encode('utf-8')
+                key = key.encode('utf-8')
                 if val != wanted and self.dest.rows > 0:
                     m =  "Metadata in destination stream:\n"
                     m += "  %s = %s\n" % (key, val)