Don't undelete when unlinking a deleted shot.

attract/shots/__init__.py

@@ -244,6 +244,12 @@ def patch_shot(node_id, patch):
             node_setattr(node, key, value)
     else:
         # Remaining operations are for marking as 'in use' or 'not in use'.
+        if node.get('_deleted', False) and op == u'unlink':
+            # We won't undelete a node in response to an unlink request.
+            return pillar.api.utils.jsonify({'_deleted': True,
+                                             '_etag': node['_etag'],
+                                             '_id': node['_id']})
+
         used_in_edit = {
             u'unlink': False,
             u'relink': True,
@@ -255,9 +261,6 @@ def patch_shot(node_id, patch):
     return pillar.api.utils.jsonify(r, status=status)
 
 
-
-
-
 def assert_is_valid_patch(patch):
     """Raises an exception when the patch isn't valid."""
 

tests/test_shots.py

@@ -355,6 +355,28 @@ class PatchShotTest(AbstractShotTest):
         dbnode = self.get(url, auth_token='token').json()
         self.assertFalse(dbnode['properties']['used_in_edit'])
 
+    @responses.activate
+    def test_patch_unlink_deleted(self):
+        """Unlinking a deleted shot shouldn't undelete it.
+
+        We implement PATCH by changing then PUTing, which undeletes by default.
+        """
+
+        shot = self.create_shot()
+        self.create_valid_auth_token(ctd.EXAMPLE_PROJECT_OWNER_ID, 'token')
+
+        url = '/api/nodes/%s' % shot._id
+
+        # Delete (and verify deletion)
+        self.delete(url, auth_token='token',
+                    headers={'If-Match': shot['_etag']},
+                    expected_status=204)
+        self.get(url, auth_token='token', expected_status=404)
+
+        patch = {'op': 'unlink'}
+        self.patch(url, json=patch, auth_token='token')
+        self.get(url, auth_token='token', expected_status=404)
+
     @responses.activate
     def test_patch_relink(self):
         shot = self.create_shot()