Merge forwardport of #11962 to 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/11962.patch (created by @RomaKis) based on commit(s):
  1. 1717df4
  2. c438c17
  3. 42d9b52

Fixed GitHub Issues in 2.3-develop branch:
  - #11793: Magento2.1.5 admin shipping report shows wrong currency code (reported by @pushparaj100)

app/code/Magento/Reports/Block/Adminhtml/Grid/AbstractGrid.php

@@ -363,12 +363,11 @@ public function setStoreIds($storeIds)
     public function getCurrentCurrencyCode()
     {
         if ($this->_currentCurrencyCode === null) {
-            $this->_currentCurrencyCode = count(
-                $this->_storeIds
-            ) > 0 ? $this->_storeManager->getStore(
-                array_shift($this->_storeIds)
-            )->getBaseCurrencyCode() : $this->_storeManager->getStore()->getBaseCurrencyCode();
+            $this->_currentCurrencyCode = count($this->_storeIds) > 0
+                ? $this->_storeManager->getStore(array_shift($this->_storeIds))->getCurrentCurrencyCode()
+                : $this->_storeManager->getStore()->getBaseCurrencyCode();
         }
+
         return $this->_currentCurrencyCode;
     }
 

app/code/Magento/Reports/Test/Unit/Block/Adminhtml/Grid/AbstractGridTest.php

@@ -0,0 +1,91 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Reports\Test\Unit\Block\Adminhtml\Grid;
+
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+
+/**
+ * Test for class \Magento\Reports\Block\Adminhtml\Grid\AbstractGrid.
+ */
+class AbstractGridTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var \Magento\Reports\Block\Adminhtml\Grid\AbstractGrid|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $model;
+
+    /**
+     * @var \Magento\Store\Model\StoreManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $storeManagerMock;
+
+    protected function setUp()
+    {
+        $objectManager = new ObjectManager($this);
+
+        $this->storeManagerMock = $this->getMockForAbstractClass(
+            \Magento\Store\Model\StoreManagerInterface::class,
+            [],
+            '',
+            true,
+            true,
+            true,
+            ['getStore']
+        );
+
+        $this->model = $objectManager->getObject(
+            \Magento\Reports\Block\Adminhtml\Grid\AbstractGrid::class,
+            ['_storeManager' => $this->storeManagerMock]
+        );
+    }
+
+    /**
+     * @param $storeIds
+     *
+     * @dataProvider getCurrentCurrencyCodeDataProvider
+     */
+    public function testGetCurrentCurrencyCode($storeIds)
+    {
+        $storeMock = $this->getMockForAbstractClass(
+            \Magento\Store\Api\Data\StoreInterface::class,
+            [],
+            '',
+            true,
+            true,
+            true,
+            ['getBaseCurrencyCode', 'getCurrentCurrencyCode']
+        );
+
+        $this->storeManagerMock->expects($this->once())->method('getStore')->willReturn($storeMock);
+
+        $this->model->setStoreIds($storeIds);
+
+        if ($storeIds) {
+            $storeMock->expects($this->once())->method('getCurrentCurrencyCode')->willReturn('EUR');
+            $expectedCurrencyCode = 'EUR';
+        } else {
+            $storeMock->expects($this->once())->method('getBaseCurrencyCode')->willReturn('USD');
+            $expectedCurrencyCode = 'USD';
+        }
+
+        $currencyCode = $this->model->getCurrentCurrencyCode();
+        $this->assertEquals($expectedCurrencyCode, $currencyCode);
+    }
+
+    /**
+     * DataProvider for testGetCurrentCurrencyCode.
+     *
+     * @return array
+     */
+    public function getCurrentCurrencyCodeDataProvider()
+    {
+        return [
+            [[]],
+            [[2]],
+        ];
+    }
+}