forum: fix mods not being able to lock forum topics.

app/models/forum_post.rb

@@ -18,7 +18,6 @@ class ForumPost < ApplicationRecord
   validates_presence_of :body
   validate :validate_topic_is_unlocked
   validate :topic_is_not_restricted, :on => :create
-  before_destroy :validate_topic_is_unlocked
   after_save :delete_topic_if_original_post
   after_update(:if => ->(rec) {rec.updater_id != rec.creator_id}) do |rec|
     ModAction.log("#{CurrentUser.name} updated forum ##{rec.id}", :forum_post_update)
@@ -103,12 +102,8 @@ class ForumPost < ApplicationRecord
   end
 
   def validate_topic_is_unlocked
-    return if creator.is_moderator?
-    return if topic.nil?
-
-    if topic.is_locked?
+    if topic.is_locked? && !updater.is_moderator?
       errors[:topic] << "is locked"
-      throw :abort
     end
   end
 

test/functional/forum_topics_controller_test.rb

@@ -211,6 +211,15 @@ class ForumTopicsControllerTest < ActionDispatch::IntegrationTest
       end
     end
 
+    context "update action" do
+      should "allow mods to lock forum topics" do
+        put_auth forum_topic_path(@forum_topic), @mod, params: { forum_topic: { is_locked: true }}
+
+        assert_redirected_to forum_topic_path(@forum_topic)
+        assert_equal(true, @forum_topic.reload.is_locked)
+      end
+    end
+
     context "destroy action" do
       setup do
         as_user do

test/unit/forum_post_test.rb

@@ -104,21 +104,20 @@ class ForumPostTest < ActiveSupport::TestCase
 
     context "belonging to a locked topic" do
       setup do
-        @post = FactoryBot.create(:forum_post, :topic_id => @topic.id, :body => "zzz")
-        @topic.update_attribute(:is_locked, true)
-        @post.reload
+        @post = create(:forum_post, topic: @topic, body: "zzz")
+        @topic.update(is_locked: true)
       end
 
       should "not be updateable" do
         @post.update(body: "xxx")
-        @post.reload
-        assert_equal("zzz", @post.body)
+        assert_equal(true, @post.invalid?)
+        assert_equal("zzz", @post.reload.body)
       end
 
       should "not be deletable" do
-        assert_difference("ForumPost.count", 0) do
-          @post.destroy
-        end
+        @post.delete!
+        assert_equal(true, @post.invalid?)
+        assert_equal(false, @post.reload.is_deleted)
       end
     end