FIX: Staff can create and edit posts even if a topic is in slow mode. (#11057)

Additionally, ninja edits are no longer restricted.

lib/guardian/topic_guardian.rb

@@ -219,4 +219,8 @@ module TopicGuardian
     can_perform_action_available_to_group_moderators?(topic)
   end
 
+  def affected_by_slow_mode?(topic)
+    topic&.slow_mode_seconds.to_i > 0 && @user.human? && !is_staff?
+  end
+
 end

lib/post_creator.rb

@@ -159,7 +159,7 @@ class PostCreator
         return false
       end
 
-      if @topic&.slow_mode_seconds.to_i > 0
+      if guardian.affected_by_slow_mode?(@topic)
         tu = TopicUser.find_by(user: @user, topic: @topic)
 
         if tu&.last_posted_at

lib/post_revisor.rb

@@ -144,6 +144,11 @@ class PostRevisor
     @revised_at = @opts[:revised_at] || Time.now
     @last_version_at = @post.last_version_at || Time.now
 
+    if guardian.affected_by_slow_mode?(@topic) && !ninja_edit?
+      @post.errors.add(:base, I18n.t("cannot_edit_on_slow_mode"))
+      return false
+    end
+
     @version_changed = false
     @post_successfully_saved = true
 
@@ -194,7 +199,7 @@ class PostRevisor
 
     # We log staff/group moderator edits to posts
     if (
-      (@editor.staff? || (@post.is_category_description? && Guardian.new(@editor).can_edit_category_description?(@post.topic.category))) &&
+      (@editor.staff? || (@post.is_category_description? && guardian.can_edit_category_description?(@post.topic.category))) &&
       @editor.id != @post.user_id &&
       @fields.has_key?('raw') &&
       !@opts[:skip_staff_log]
@@ -639,4 +644,8 @@ class PostRevisor
     @post_successfully_saved && !@topic_changes.errored?
   end
 
+  def guardian
+    @guardian ||= Guardian.new(@editor)
+  end
+
 end