From 81b5d61fa773ea7318a6d93ba62f82967daef631 Mon Sep 17 00:00:00 2001
From: Guo Xiang Tan <tgx_world@hotmail.com>
Date: Mon, 28 May 2018 17:06:47 +0800
Subject: [PATCH] FIX: `topic_destroyed` web hook couldn't find topic.

---
 lib/topic_view.rb                  | 21 +++++++++++++--------
 spec/components/topic_view_spec.rb |  5 +++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/lib/topic_view.rb b/lib/topic_view.rb
index 3c3dbd4e84b..d2bf87de10b 100644
--- a/lib/topic_view.rb
+++ b/lib/topic_view.rb
@@ -37,15 +37,16 @@ class TopicView
     wpcf.flatten.uniq
   end
 
-  def initialize(topic_id, user = nil, options = {})
-    @message_bus_last_id = MessageBus.last_id("/topic/#{topic_id}")
+  def initialize(topic_or_topic_id, user = nil, options = {})
+    @topic = find_topic(topic_or_topic_id)
     @user = user
     @guardian = Guardian.new(@user)
-    @topic = find_topic(topic_id)
-    @print = options[:print].present?
 
     check_and_raise_exceptions
 
+    @message_bus_last_id = MessageBus.last_id("/topic/#{@topic.id}")
+    @print = options[:print].present?
+
     options.each do |key, value|
       self.instance_variable_set("@#{key}".to_sym, value)
     end
@@ -435,10 +436,14 @@ class TopicView
     @posts
   end
 
-  def find_topic(topic_id)
-    # with_deleted covered in #check_and_raise_exceptions
-    finder = Topic.with_deleted.where(id: topic_id).includes(:category)
-    finder.first
+  def find_topic(topic_or_topic_id)
+    if topic_or_topic_id.is_a?(Topic)
+      topic_or_topic_id
+    else
+      # with_deleted covered in #check_and_raise_exceptions
+      finder = Topic.with_deleted.where(id: topic_or_topic_id).includes(:category)
+      finder.first
+    end
   end
 
   def unfiltered_posts
diff --git a/spec/components/topic_view_spec.rb b/spec/components/topic_view_spec.rb
index 830b2a2c36b..06fb8099a08 100644
--- a/spec/components/topic_view_spec.rb
+++ b/spec/components/topic_view_spec.rb
@@ -13,6 +13,11 @@ describe TopicView do
     expect { TopicView.new(1231232, evil_trout) }.to raise_error(Discourse::NotFound)
   end
 
+  it "accepts a topic or a topic id" do
+    expect(TopicView.new(topic, evil_trout).topic).to eq(topic)
+    expect(TopicView.new(topic.id, evil_trout).topic).to eq(topic)
+  end
+
   # see also spec/controllers/topics_controller_spec.rb TopicsController::show::permission errors
   it "raises an error if the user can't see the topic" do
     Guardian.any_instance.expects(:can_see?).with(topic).returns(false)