From 96700d55a45a81d399b01b36fcd79585262b9b89 Mon Sep 17 00:00:00 2001
From: Isaac Janzen <50783505+janzenisaac@users.noreply.github.com>
Date: Tue, 25 Apr 2023 10:08:00 -0500
Subject: [PATCH] FIX: Safely return from missing post on
 `check_dont_feed_the_trolls` (#21238)

---
 lib/composer_messages_finder.rb           | 2 +-
 spec/lib/composer_messages_finder_spec.rb | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/composer_messages_finder.rb b/lib/composer_messages_finder.rb
index 78841a91385..4bba013a5c0 100644
--- a/lib/composer_messages_finder.rb
+++ b/lib/composer_messages_finder.rb
@@ -233,7 +233,7 @@ class ComposerMessagesFinder
       if @details[:post_id]
         Post.find_by(id: @details[:post_id])
       else
-        @topic.first_post
+        @topic&.first_post
       end
 
     return if post.blank?
diff --git a/spec/lib/composer_messages_finder_spec.rb b/spec/lib/composer_messages_finder_spec.rb
index a95370e86a2..b6ab99a1acd 100644
--- a/spec/lib/composer_messages_finder_spec.rb
+++ b/spec/lib/composer_messages_finder_spec.rb
@@ -395,6 +395,11 @@ RSpec.describe ComposerMessagesFinder do
         )
       expect(finder.check_dont_feed_the_trolls).to be_present
     end
+
+    it "safely returns from not finding a post" do
+      finder = ComposerMessagesFinder.new(user, composer_action: "reply", topic_id: nil)
+      expect(finder.check_dont_feed_the_trolls).to be_blank
+    end
   end
 
   describe ".check_get_a_room" do