Merge branch 'bugfix/activitypub-public' into 'develop'

activitypub addressing improvements

Closes #730 and #739

See merge request pleroma/pleroma!953

lib/pleroma/user.ex

@@ -104,9 +104,8 @@ def ap_id(%User{nickname: nickname}) do
     "#{Web.base_url()}/users/#{nickname}"
   end
 
-  def ap_followers(%User{} = user) do
-    "#{ap_id(user)}/followers"
-  end
+  def ap_followers(%User{follower_address: fa}) when is_binary(fa), do: fa
+  def ap_followers(%User{} = user), do: "#{ap_id(user)}/followers"
 
   def user_info(%User{} = user) do
     oneself = if user.local, do: 1, else: 0

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -86,10 +86,14 @@ def fix_object(object) do
   end
 
   def fix_addressing_list(map, field) do
-    if is_binary(map[field]) do
-      map
-      |> Map.put(field, [map[field]])
-    else
+    cond do
+      is_binary(map[field]) ->
+        Map.put(map, field, [map[field]])
+
+      is_nil(map[field]) ->
+        Map.put(map, field, [])
+
+      true ->
         map
     end
   end
@@ -128,13 +132,42 @@ def fix_explicit_addressing(object) do
     |> fix_explicit_addressing(explicit_mentions)
   end
 
+  # if as:Public is addressed, then make sure the followers collection is also addressed
+  # so that the activities will be delivered to local users.
+  def fix_implicit_addressing(%{"to" => to, "cc" => cc} = object, followers_collection) do
+    recipients = to ++ cc
+
+    if followers_collection not in recipients do
+      cond do
+        "https://www.w3.org/ns/activitystreams#Public" in cc ->
+          to = to ++ [followers_collection]
+          Map.put(object, "to", to)
+
+        "https://www.w3.org/ns/activitystreams#Public" in to ->
+          cc = cc ++ [followers_collection]
+          Map.put(object, "cc", cc)
+
+        true ->
+          object
+      end
+    else
+      object
+    end
+  end
+
+  def fix_implicit_addressing(object, _), do: object
+
   def fix_addressing(object) do
+    %User{} = user = User.get_or_fetch_by_ap_id(object["actor"])
+    followers_collection = User.ap_followers(user)
+
     object
     |> fix_addressing_list("to")
     |> fix_addressing_list("cc")
     |> fix_addressing_list("bto")
     |> fix_addressing_list("bcc")
     |> fix_explicit_addressing
+    |> fix_implicit_addressing(followers_collection)
   end
 
   def fix_actor(%{"attributedTo" => actor} = object) do
@@ -922,7 +955,8 @@ defp strip_internal_tags(%{"tag" => tags} = object) do
   defp strip_internal_tags(object), do: object
 
   defp user_upgrade_task(user) do
-    old_follower_address = User.ap_followers(user)
+    # we pass a fake user so that the followers collection is stripped away
+    old_follower_address = User.ap_followers(%User{nickname: user.nickname})
 
     q =
       from(

test/web/activity_pub/transmogrifier_test.exs

@@ -335,6 +335,53 @@ test "it does not clobber the addressing on announce activities" do
       assert data["to"] == ["http://mastodon.example.org/users/admin/followers"]
     end
 
+    test "it ensures that as:Public activities make it to their followers collection" do
+      user = insert(:user)
+
+      data =
+        File.read!("test/fixtures/mastodon-post-activity.json")
+        |> Poison.decode!()
+        |> Map.put("actor", user.ap_id)
+        |> Map.put("to", ["https://www.w3.org/ns/activitystreams#Public"])
+        |> Map.put("cc", [])
+
+      object =
+        data["object"]
+        |> Map.put("attributedTo", user.ap_id)
+        |> Map.put("to", ["https://www.w3.org/ns/activitystreams#Public"])
+        |> Map.put("cc", [])
+
+      data = Map.put(data, "object", object)
+
+      {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
+
+      assert data["cc"] == [User.ap_followers(user)]
+    end
+
+    test "it ensures that address fields become lists" do
+      user = insert(:user)
+
+      data =
+        File.read!("test/fixtures/mastodon-post-activity.json")
+        |> Poison.decode!()
+        |> Map.put("actor", user.ap_id)
+        |> Map.put("to", nil)
+        |> Map.put("cc", nil)
+
+      object =
+        data["object"]
+        |> Map.put("attributedTo", user.ap_id)
+        |> Map.put("to", nil)
+        |> Map.put("cc", nil)
+
+      data = Map.put(data, "object", object)
+
+      {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
+
+      assert !is_nil(data["to"])
+      assert !is_nil(data["cc"])
+    end
+
     test "it works for incoming update activities" do
       data = File.read!("test/fixtures/mastodon-post-activity.json") |> Poison.decode!()