From 1aec473133d1ec2558914aafacde91e6f29ace3c Mon Sep 17 00:00:00 2001
From: Tiago Sampaio <tiago@tiagosampaio.com>
Date: Fri, 22 Jun 2018 15:45:25 -0300
Subject: [PATCH] Better way to retrieve the first tab ID if active tab is
 empty.

---
 app/code/Magento/Backend/Block/Widget/Tabs.php | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/app/code/Magento/Backend/Block/Widget/Tabs.php b/app/code/Magento/Backend/Block/Widget/Tabs.php
index 88508d52151b9..b577d80bb5db6 100644
--- a/app/code/Magento/Backend/Block/Widget/Tabs.php
+++ b/app/code/Magento/Backend/Block/Widget/Tabs.php
@@ -234,19 +234,16 @@ protected function _beforeToHtml()
     {
         $this->_tabs = $this->reorderTabs();
         
-        if ($this->_activeTab === null) {
-            /** @var TabInterface $tab */
-            foreach ($this->_tabs as $tab) {
-                $this->_activeTab = $tab->getId();
-                break;
-            }
-        }
-        
         if ($activeTab = $this->getRequest()->getParam('active_tab')) {
             $this->setActiveTab($activeTab);
         } elseif ($activeTabId = $this->_authSession->getActiveTabId()) {
             $this->_setActiveTab($activeTabId);
         }
+
+        if ($this->_activeTab === null && !empty($this->_tabs)) {
+            /** @var TabInterface $tab */
+            $this->_activeTab = (reset($this->_tabs))->getId();
+        }
         
         $this->assign('tabs', $this->_tabs);
         return parent::_beforeToHtml();
@@ -256,7 +253,7 @@ protected function _beforeToHtml()
     /**
      * @return array
      */
-    protected function reorderTabs()
+    private function reorderTabs()
     {
         $orderByIdentity = [];
         $orderByPosition = [];