FIX: Parsing non-existent feed should not fail

app/jobs/scheduled/poll_feed.rb

@@ -89,6 +89,8 @@ module Jobs
 
       def parsed_feed
         raw_feed, encoding = fetch_rss
+        return nil if raw_feed.nil?
+
         encoded_feed = Encodings.try_utf8(raw_feed, encoding) if encoding
         encoded_feed = Encodings.to_utf8(raw_feed) unless encoded_feed
 

spec/jobs/poll_feed_spec.rb

@@ -137,6 +137,17 @@ describe Jobs::PollFeed do
       include_examples 'topic creation based on the the feed'
     end
 
+    it "aborts when it can't fetch the feed" do
+      SiteSetting.feed_polling_enabled = true
+      SiteSetting.feed_polling_url = 'https://blog.discourse.org/feed/atom/'
+      SiteSetting.embed_by_username = 'eviltrout'
+
+      stub_request(:head, SiteSetting.feed_polling_url).to_return(status: 404)
+      stub_request(:get, SiteSetting.feed_polling_url).to_return(status: 404)
+
+      expect { poller.poll_feed }.to_not change { Topic.count }
+    end
+
     context 'encodings' do
       before do
         SiteSetting.feed_polling_enabled = true