pundit: convert forum topics / forum posts to pundit.

Fix it being possible for users to delete or undelete their own forum
posts and topics, even if they were deleted by a mod.

app/controllers/forum_posts_controller.rb

@@ -1,25 +1,14 @@
 class ForumPostsController < ApplicationController
   respond_to :html, :xml, :json, :js
-  before_action :member_only, :except => [:index, :show, :search]
-  before_action :load_post, :only => [:edit, :show, :update, :destroy, :undelete]
-  before_action :check_min_level, :only => [:edit, :show, :update, :destroy, :undelete]
   skip_before_action :api_check
 
   def new
-    if params[:topic_id]
-      @forum_topic = ForumTopic.find(params[:topic_id])
-      raise User::PrivilegeError.new unless @forum_topic.visible?(CurrentUser.user)
-    end
-    if params[:post_id]
-      quoted_post = ForumPost.find(params[:post_id])
-      raise User::PrivilegeError.new unless quoted_post.topic.visible?(CurrentUser.user)
-    end
-    @forum_post = ForumPost.new_reply(params)
+    @forum_post = authorize ForumPost.new_reply(params)
     respond_with(@forum_post)
   end
 
   def edit
-    check_privilege(@forum_post)
+    @forum_post = authorize ForumPost.find(params[:id])
     respond_with(@forum_post)
   end
 
@@ -34,6 +23,8 @@ class ForumPostsController < ApplicationController
   end
 
   def show
+    @forum_post = authorize ForumPost.find(params[:id])
+
     respond_with(@forum_post) do |format|
       format.html do
         page = @forum_post.forum_topic_page
@@ -44,51 +35,29 @@ class ForumPostsController < ApplicationController
   end
 
   def create
-    @forum_post = ForumPost.create(forum_post_params(:create).merge(creator: CurrentUser.user))
+    @forum_post = authorize ForumPost.new(creator: CurrentUser.user, topic_id: params.dig(:forum_post, :topic_id))
+    @forum_post.update(permitted_attributes(@forum_post))
+
     page = @forum_post.topic.last_page if @forum_post.topic.last_page > 1
     respond_with(@forum_post, :location => forum_topic_path(@forum_post.topic, :page => page))
   end
 
   def update
-    check_privilege(@forum_post)
-    @forum_post.update(forum_post_params(:update))
+    @forum_post = authorize ForumPost.find(params[:id])
+    @forum_post.update(permitted_attributes(@forum_post))
     page = @forum_post.forum_topic_page if @forum_post.forum_topic_page > 1
     respond_with(@forum_post, :location => forum_topic_path(@forum_post.topic, :page => page, :anchor => "forum_post_#{@forum_post.id}"))
   end
 
   def destroy
-    check_privilege(@forum_post)
+    @forum_post = authorize ForumPost.find(params[:id])
     @forum_post.delete!
     respond_with(@forum_post)
   end
 
   def undelete
-    check_privilege(@forum_post)
+    @forum_post = authorize ForumPost.find(params[:id])
     @forum_post.undelete!
     respond_with(@forum_post)
   end
-
-  private
-
-  def load_post
-    @forum_post = ForumPost.find(params[:id])
-    @forum_topic = @forum_post.topic
-  end
-
-  def check_min_level
-    raise User::PrivilegeError if CurrentUser.user.level < @forum_topic.min_level
-  end
-
-  def check_privilege(forum_post)
-    if !forum_post.editable_by?(CurrentUser.user)
-      raise User::PrivilegeError
-    end
-  end
-
-  def forum_post_params(context)
-    permitted_params = [:body]
-    permitted_params += [:topic_id] if context == :create
-
-    params.require(:forum_post).permit(permitted_params)
-  end
 end