Correct bug in image thumbnailing routine #318

When a thumbnail is orphaned and needed to be removed, we accidentally
were running an image check on it and dying with an error.  Now, we do
image checks first, *then* add and delete thumbnails for the current
family as appropriate.

bin/s3imagecheck.py

@@ -49,14 +49,14 @@ def check_family(operator, family_name):
         thumbdir = operator.make_thumbdir(thumbsize, family_name)
         thumbs = operator.list_thumbnails(thumbdir)
 
+        check_images(operator, thumbs)
+
         for thumb in thumbs:
             thumb_name = name_of(thumb)
             if thumb_name not in image_names:
                 operator.error(thumb, 'Thumbnail is an orphan; deleting')
                 thumb.delete()
 
-        check_images(operator, thumbs)
-
         thumb_names = names_of(thumbs)
         for image in images:
             if name_of(image) not in thumb_names: