fixed disabled guest checkout issue in case of downloadable product

app/code/Magento/Downloadable/Observer/IsAllowedGuestCheckoutObserver.php

@@ -8,12 +8,20 @@
 use Magento\Framework\Event\ObserverInterface;
 use Magento\Store\Model\ScopeInterface;
 
+/**
+ * Check is allowed guest checkout for downloadable items.
+ */
 class IsAllowedGuestCheckoutObserver implements ObserverInterface
 {
     /**
      *  Xml path to disable checkout
      */
-    const XML_PATH_DISABLE_GUEST_CHECKOUT = 'catalog/downloadable/disable_guest_checkout';
+    private const XML_PATH_DISABLE_GUEST_CHECKOUT = 'catalog/downloadable/disable_guest_checkout';
+
+    /**
+     *  Xml path to get downloadable Shareable setting
+     */
+    private const XML_PATH_DOWNLOADABLE_SHAREABLE = 'catalog/downloadable/shareable';
 
     /**
      * Core store config
@@ -46,7 +54,12 @@ public function execute(\Magento\Framework\Event\Observer $observer)
             self::XML_PATH_DISABLE_GUEST_CHECKOUT,
             ScopeInterface::SCOPE_STORE,
             $store
-        )) {
+        ) && $this->_scopeConfig->isSetFlag(
+            self::XML_PATH_DOWNLOADABLE_SHAREABLE,
+            ScopeInterface::SCOPE_STORE,
+            $store
+        )
+        ) {
             return $this;
         }
 

app/code/Magento/Downloadable/Test/Mftf/Data/CatalogConfigData.xml

@@ -18,4 +18,9 @@
         <data key="scope_id">0</data>
         <data key="value">1</data>
     </entity>
+    <entity name="EnableShareableDownloadableItems">
+        <data key="path">catalog/downloadable/shareable</data>
+        <data key="scope_id">0</data>
+        <data key="value">1</data>
+    </entity>
 </entities>

app/code/Magento/Downloadable/Test/Mftf/Test/LinkDownloadableProductFromGuestToCustomerTest.xml

@@ -19,6 +19,7 @@
         </annotations>
         <before>
             <magentoCLI command="config:set {{EnableGuestCheckoutWithDownloadableItems.path}} {{EnableGuestCheckoutWithDownloadableItems.value}}" stepKey="enableGuestCheckoutWithDownloadableItems" />
+            <magentoCLI command="config:set {{EnableShareableDownloadableItems.path}} {{EnableShareableDownloadableItems.value}}" stepKey="enableShareableDownloadableItems" />
             <createData entity="_defaultCategory" stepKey="createCategory"/>
             <createData entity="DownloadableProductWithOneLink" stepKey="createProduct">
                 <requiredEntity createDataKey="createCategory"/>

app/code/Magento/Downloadable/Test/Unit/Observer/IsAllowedGuestCheckoutObserverTest.php

@@ -176,7 +176,7 @@ public function testIsAllowedGuestCheckoutConfigSetToFalse()
             ->method('getResult')
             ->will($this->returnValue($this->resultMock));
 
-        $this->scopeConfig->expects($this->once())
+        $this->scopeConfig->expects($this->at(0))
             ->method('isSetFlag')
             ->with(
                 IsAllowedGuestCheckoutObserver::XML_PATH_DISABLE_GUEST_CHECKOUT,
@@ -185,6 +185,15 @@ public function testIsAllowedGuestCheckoutConfigSetToFalse()
             )
             ->willReturn(false);
 
+        $this->scopeConfig->expects($this->at(1))
+            ->method('isSetFlag')
+            ->with(
+                IsAllowedGuestCheckoutObserver::XML_PATH_DOWNLOADABLE_SHAREABLE,
+                ScopeInterface::SCOPE_STORE,
+                $this->storeMock
+            )
+            ->willReturn(true);
+
         $this->observerMock->expects($this->exactly(2))
             ->method('getEvent')
             ->will($this->returnValue($this->eventMock));