From 54287552db770cf58507f9fc37f57ebfb7e915bf Mon Sep 17 00:00:00 2001
From: ganmacs <ganmacs@gmail.com>
Date: Tue, 9 Aug 2016 11:08:30 +0900
Subject: [PATCH] Add a check that primary and secondary use `custom_format` or
 not

---
 lib/fluent/plugin/output.rb |  2 +-
 test/test_output.rb         | 27 ++++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/lib/fluent/plugin/output.rb b/lib/fluent/plugin/output.rb
index 32bc6ef3d0..1a1100f6a8 100644
--- a/lib/fluent/plugin/output.rb
+++ b/lib/fluent/plugin/output.rb
@@ -301,7 +301,7 @@ def configure(conf)
           @secondary.acts_as_secondary(self)
           @secondary.configure(secondary_conf)
           @secondary.router = router if @secondary.has_router?
-          if self.class != @secondary.class
+          if (self.class != @secondary.class) && (@custom_format || @secondary.implement?(:custom_format))
             log.warn "secondary type should be same with primary one", primary: self.class.to_s, secondary: @secondary.class.to_s
           end
         else
diff --git a/test/test_output.rb b/test/test_output.rb
index 3bb9160bfd..79a8a5f8af 100644
--- a/test/test_output.rb
+++ b/test/test_output.rb
@@ -95,12 +95,37 @@ def write(chunk)
     end
 
     def test_secondary
-      d = create_driver(CONFIG + %[
+      d = Fluent::Test::BufferedOutputTestDriver.new(Fluent::BufferedOutput) do
+        def write(chunk)
+          chunk.read
+        end
+      end
+
+      mock(d.instance.log).warn("secondary type should be same with primary one",
+                                { primary: d.instance.class.to_s, secondary: "Fluent::Plugin::Test2Output" })
+      d.configure(CONFIG + %[
+        <secondary>
+          type test2
+          name c0
+        </secondary>
+      ])
+
+      assert_not_nil d.instance.instance_variable_get(:@secondary).router
+    end
+
+    def test_secondary_with_no_warn_log
+      # ObjectBufferedOutput doesn't implemnt `custom_filter`
+      d = Fluent::Test::BufferedOutputTestDriver.new(Fluent::ObjectBufferedOutput)
+
+      mock(d.instance.log).warn("secondary type should be same with primary one",
+                                { primary: d.instance.class.to_s, secondary: "Fluent::Plugin::Test2Output" }).never
+      d.configure(CONFIG + %[
         <secondary>
           type test2
           name c0
         </secondary>
       ])
+
       assert_not_nil d.instance.instance_variable_get(:@secondary).router
     end
   end