CommonAPI: Change public->private implicit addressing.

This will not add the OP to the `to` field anymore when going from
public to private.

lib/pleroma/web/common_api/utils.ex

@@ -102,7 +102,8 @@ def get_to_and_cc(user, mentioned_users, inReplyTo, "private", _) do
   end
 
   def get_to_and_cc(_user, mentioned_users, inReplyTo, "direct", _) do
-    if inReplyTo do
+    # If the OP is a DM already, add the implicit actor.
+    if inReplyTo && Visibility.is_direct?(inReplyTo) do
       {Enum.uniq([inReplyTo.data["actor"] | mentioned_users]), []}
     else
       {mentioned_users, []}

test/web/common_api/common_api_test.exs

@@ -335,6 +335,32 @@ test "it does not allow replies to direct messages that are not direct messages
       end)
     end
 
+    test "replying with a direct message will NOT auto-add the author of the reply to the recipient list" do
+      user = insert(:user)
+      other_user = insert(:user)
+      third_user = insert(:user)
+
+      {:ok, post} = CommonAPI.post(user, %{status: "I'm stupid"})
+
+      {:ok, open_answer} =
+        CommonAPI.post(other_user, %{status: "No ur smart", in_reply_to_status_id: post.id})
+
+      # The OP is implicitly added
+      assert user.ap_id in open_answer.recipients
+
+      {:ok, secret_answer} =
+        CommonAPI.post(other_user, %{
+          status: "lol, that guy really is stupid, right, @#{third_user.nickname}?",
+          in_reply_to_status_id: post.id,
+          visibility: "direct"
+        })
+
+      assert third_user.ap_id in secret_answer.recipients
+
+      # The OP is not added
+      refute user.ap_id in secret_answer.recipients
+    end
+
     test "it allows to address a list" do
       user = insert(:user)
       {:ok, list} = Pleroma.List.create("foo", user)

test/web/common_api/common_api_utils_test.exs

@@ -297,11 +297,10 @@ test "for private posts, a reply" do
 
       {to, cc} = Utils.get_to_and_cc(user, mentions, activity, "private", nil)
 
-      assert length(to) == 3
+      assert length(to) == 2
       assert Enum.empty?(cc)
 
       assert mentioned_user.ap_id in to
-      assert third_user.ap_id in to
       assert user.follower_address in to
     end
 
@@ -327,6 +326,15 @@ test "for direct posts, a reply" do
 
       {to, cc} = Utils.get_to_and_cc(user, mentions, activity, "direct", nil)
 
+      assert length(to) == 1
+      assert Enum.empty?(cc)
+
+      assert mentioned_user.ap_id in to
+
+      {:ok, direct_activity} = CommonAPI.post(third_user, %{status: "uguu", visibility: "direct"})
+
+      {to, cc} = Utils.get_to_and_cc(user, mentions, direct_activity, "direct", nil)
+
       assert length(to) == 2
       assert Enum.empty?(cc)