Add user muted status info to MastodonAPI.

lib/pleroma/user.ex

@@ -960,6 +960,7 @@ def unblock(blocker, %{ap_id: ap_id}) do
     update_and_set_cache(cng)
   end
 
+  def mutes?(nil, _), do: false
   def mutes?(user, %{ap_id: ap_id}), do: Enum.member?(user.info.mutes, ap_id)
 
   def blocks?(user, %{ap_id: ap_id}) do

lib/pleroma/web/mastodon_api/views/status_view.ex

@@ -168,7 +168,7 @@ def render("status.json", %{activity: %{data: %{"object" => object}} = activity}
       reblogged: present?(repeated),
       favourited: present?(favorited),
       bookmarked: present?(bookmarked),
-      muted: CommonAPI.thread_muted?(user, activity),
+      muted: CommonAPI.thread_muted?(user, activity) || User.mutes?(opts[:for], user),
       pinned: pinned?(activity, user),
       sensitive: sensitive,
       spoiler_text: object["summary"] || "",

test/web/mastodon_api/status_view_test.exs

@@ -126,6 +126,22 @@ test "a note activity" do
     assert status == expected
   end
 
+  test "tells if the message is muted for some reason" do
+    user = insert(:user)
+    other_user = insert(:user)
+
+    {:ok, user} = User.mute(user, other_user)
+
+    {:ok, activity} = CommonAPI.post(other_user, %{"status" => "test"})
+    status = StatusView.render("status.json", %{activity: activity})
+
+    assert status.muted == false
+
+    status = StatusView.render("status.json", %{activity: activity, for: user})
+
+    assert status.muted == true
+  end
+
   test "a reply" do
     note = insert(:note_activity)
     user = insert(:user)