FIX: `DiscourseRedis::FallbackHandler` not restricting number of threads spawned.

lib/discourse_redis.rb

@@ -18,7 +18,7 @@ class DiscourseRedis
 
     def verify_master
       synchronize do
-        return if @running && !recently_checked?
+        return if @running || recently_checked?
         @running = true
       end
 
@@ -58,7 +58,7 @@ class DiscourseRedis
 
     def recently_checked?
       if @last_checked
-        Time.zone.now > (@last_checked + 5.seconds)
+        Time.zone.now <= (@last_checked + 5.seconds)
       else
         false
       end

spec/components/discourse_redis_spec.rb

@@ -96,6 +96,14 @@ describe DiscourseRedis do
           fallback_handler.master = true
         end
       end
+
+      it "should restrict the number of checks" do
+        expect { fallback_handler.verify_master }.to change { Thread.list.count }.by(1)
+        expect(fallback_handler.master).to eq(true)
+
+        fallback_handler.master = false
+        expect { fallback_handler.verify_master }.to_not change { Thread.list.count }
+      end
     end
   end
 end