Move check that metadata exists earlier

Because of gstreamer-1.0 we need to migrate from old format of storing
metadata to new one. It seems that there are cases when original
metadata is empty for some reason.

The patch adds an earlier check that original metadata exists, skipping
everything is it doesn't.

Closes bug 5071

diff --git a/mediagoblin/media_types/video/migrations.py b/mediagoblin/media_types/video/migrations.py
index 8088220b2a84e2339941a01cbc9bc23ce3eaa0a1..2445cd4d8f7daaf5edfffd8f60191c7f7e0f93fa 100644 (file)
--- a/mediagoblin/media_types/video/migrations.py
+++ b/mediagoblin/media_types/video/migrations.py
@@ -59,11 +59,11 @@ def change_metadata_format(db):
     vid_data = inspect_table(db_metadata, "video__mediadata")
 
     for row in db.execute(vid_data.select()):
-        metadata = json.loads(row.orig_metadata)
-
-        if not metadata:
+        if not row.orig_metadata:
             continue
 
+        metadata = json.loads(row.orig_metadata)
+
         # before this migration there was info about only one video or audio
         # stream. So, we store existing info as the first item in the list
         new_metadata = {'audio': [], 'video': [], 'common': {}}
@@ -85,7 +85,7 @@ def change_metadata_format(db):
                 for k, v in audio_key_map.items() if metadata.get(k))]
         new_metadata['common'] = dict((v, metadata.get(k))
                 for k, v in common_key_map.items() if metadata.get(k))
-        
+
         # 'mimetype' should be in tags
         new_metadata['common']['tags'] = {'mimetype': metadata.get('mimetype')}
         if 'tags' in metadata: