tests: fix object containment violations in the transmogrifier tests

Some objects were not completely rewritten in the tests, which caused object
containment violations.  Fix them by rewriting the object IDs to be in an
appropriate namespace.

CHANGELOG.md

@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [1.0.1] - 2019-07-14
+### Security
+- OStatus: fix an object spoofing vulnerability.
+
 ## [1.0.0] - 2019-06-29
 ### Security
 - Mastodon API: Fix display names not being sanitized

test/web/activity_pub/transmogrifier_test.exs

@@ -390,6 +390,7 @@ defmodule Pleroma.Web.ActivityPub.TransmogrifierTest do
         |> Map.put("attributedTo", user.ap_id)
         |> Map.put("to", ["https://www.w3.org/ns/activitystreams#Public"])
         |> Map.put("cc", [])
+        |> Map.put("id", user.ap_id <> "/activities/12345678")
 
       data = Map.put(data, "object", object)
 
@@ -413,6 +414,7 @@ defmodule Pleroma.Web.ActivityPub.TransmogrifierTest do
         |> Map.put("attributedTo", user.ap_id)
         |> Map.put("to", nil)
         |> Map.put("cc", nil)
+        |> Map.put("id", user.ap_id <> "/activities/12345678")
 
       data = Map.put(data, "object", object)