Don't create notifications if the user is blocked.

lib/pleroma/notification.ex

@@ -46,9 +46,11 @@ def create_notifications(_), do: {:ok, []}
 
   # TODO move to sql, too.
   def create_notification(%Activity{} = activity, %User{} = user) do
+    unless User.blocks?(user, %{ap_id: activity.data["actor"]}) do
       notification = %Notification{user_id: user.id, activity_id: activity.id}
       {:ok, notification} = Repo.insert(notification)
       notification
     end
+  end
 end
 

test/notification_test.exs

@@ -20,4 +20,15 @@ test "notifies someone when they are directly addressed" do
       assert other_notification.activity_id == activity.id
     end
   end
+
+  describe "create_notification" do
+    test "it doesn't create a notification for user if the user blocks the activity author" do
+      activity = insert(:note_activity)
+      author = User.get_by_ap_id(activity.data["actor"])
+      user = insert(:user)
+      {:ok, user} = User.block(user, author)
+
+      assert nil == Notification.create_notification(activity, user)
+    end
+  end
 end