Fix off-by-one error in repo tags pagination

Fixes #1665

endpoints/api/tag.py

@@ -47,17 +47,13 @@ class ListRepositoryTags(RepositoryParamResource):
 
     page = max(1, parsed_args.get('page', 1))
     limit = min(100, max(1, parsed_args.get('limit', 50)))
+    tags, has_additional = model.tag.list_repository_tag_history(repo, page=page, size=limit,
+                                                                 specific_tag=specific_tag)
 
-    # Note: We ask for limit+1 here, so we can check to see if there are
-    # additional pages of results.
-    tags = model.tag.list_repository_tag_history(repo, page=page, size=limit+1,
-                                                 specific_tag=specific_tag)
-
-    tags = list(tags)
     return {
-      'tags': [tag_view(tag) for tag in tags[0:limit]],
+      'tags': [tag_view(tag) for tag in tags],
       'page': page,
-      'has_additional': len(tags) >= limit
+      'has_additional': has_additional,
     }