From 8d48fd346467aa2267a97fc838d42c33a7399138 Mon Sep 17 00:00:00 2001
From: Magento EngCom Team <magento-engcom-team@magento.com>
Date: Wed, 24 Jan 2018 12:08:53 -0600
Subject: [PATCH] :arrow_double_up: Forwardport of magento/magento2#12310 to
 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/12310.patch (created by @tufahu) based on commit(s):
  1. 8fc99b164bb0717a631fe61d080ac24314d4bfd0
  2. 36dfdca9b74f9df5bb3ad1f71cc51e782f2af379
  3. 5c024025593a701df675842fe7136dbe23df59fb
  4. 2eada9caa499963cb9083d7d72602f149114dfc6
  5. e9986c5ac7abdca30c20b416913c9458d974e5ad
---
 app/code/Magento/Robots/Controller/Index/Index.php             | 1 +
 .../Magento/Robots/Test/Unit/Controller/Index/IndexTest.php    | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/app/code/Magento/Robots/Controller/Index/Index.php b/app/code/Magento/Robots/Controller/Index/Index.php
index b94626e93432d..679066d723dce 100644
--- a/app/code/Magento/Robots/Controller/Index/Index.php
+++ b/app/code/Magento/Robots/Controller/Index/Index.php
@@ -43,6 +43,7 @@ public function execute()
         /** @var Page $resultPage */
         $resultPage = $this->resultPageFactory->create(true);
         $resultPage->addHandle('robots_index_index');
+        $resultPage->setHeader('Content-Type', 'text/plain');
         return $resultPage;
     }
 }
diff --git a/app/code/Magento/Robots/Test/Unit/Controller/Index/IndexTest.php b/app/code/Magento/Robots/Test/Unit/Controller/Index/IndexTest.php
index 22a69cc13bd52..d3a7a97c7ea80 100644
--- a/app/code/Magento/Robots/Test/Unit/Controller/Index/IndexTest.php
+++ b/app/code/Magento/Robots/Test/Unit/Controller/Index/IndexTest.php
@@ -51,6 +51,9 @@ public function testExecute()
         $resultPageMock->expects($this->once())
             ->method('addHandle')
             ->with('robots_index_index');
+        $resultPageMock->expects($this->once())
+            ->method('setHeader')
+            ->with('Content-Type', 'text/plain');
 
         $this->resultPageFactory->expects($this->any())
             ->method('create')