Have all tag code add, modify and delete both old and new style tags

This preps us for being able to use the new data model with existing repositories

data/model/test/test_gc.py

@@ -12,7 +12,7 @@ from playhouse.test_utils import assert_query_count
 from data import model, database
 from data.database import (Image, ImageStorage, DerivedStorageForImage, Label, TagManifestLabel,
                            ApprBlob, Manifest, TagManifest, TagManifestToManifest, ManifestLabel,
-                           TagManifestLabelMap, ManifestBlob)
+                           TagManifestLabelMap, ManifestBlob, Tag, TagToRepositoryTag)
 from image.docker.schema1 import DockerSchema1ManifestBuilder
 from test.fixtures import *
 
@@ -223,6 +223,11 @@ def assert_gc_integrity(expect_storage_removed=True):
   for blob_row in ApprBlob.select():
     storage.get_content({preferred}, storage.blob_path(blob_row.digest))
 
+  # Ensure there are no danglings OCI tags.
+  oci_tags = {t.id for t in Tag.select()}
+  referenced_oci_tags = {t.tag_id for t in TagToRepositoryTag.select()}
+  assert not (oci_tags - referenced_oci_tags)
+
 
 def test_has_garbage(default_tag_policy, initialized_db):
   """ Remove all existing repositories, then add one without garbage, check, then add one with