ACP2E-2684: Address attribute value stored incorrectly in the magento_customercustomattributes_sales_flat_quote_address table

Author: bubasuma

app/code/Magento/Customer/Test/Unit/Model/Address/AbstractAddressTest.php

@@ -17,6 +17,8 @@
 use Magento\Directory\Model\RegionFactory;
 use Magento\Directory\Model\ResourceModel\Region\Collection;
 use Magento\Eav\Model\Config;
+use Magento\Framework\Api\AttributeInterface;
+use Magento\Framework\Api\AttributeValue;
 use Magento\Framework\Data\Collection\AbstractDb;
 use Magento\Framework\DataObject;
 use Magento\Framework\Model\Context;
@@ -434,6 +436,57 @@ public function getStreetFullDataProvider()
         ];
     }
 
+    /**
+     * @return void
+     */
+    public function testSetCustomerAttributes(): void
+    {
+        $model = $this->getMockBuilder(AbstractAddress::class)
+            ->onlyMethods(['getCustomAttributesCodes'])
+            ->disableOriginalConstructor()
+            ->getMockForAbstractClass();
+        $customAttributeFactory = $this->createMock(\Magento\Customer\Model\AttributeFactory::class);
+        $customAttributeFactory->method('create')
+            ->willReturnCallback(
+                function ($data) {
+                    return new AttributeValue($data);
+                }
+            );
+        $data = [
+            'customer_attribute1' => new AttributeValue([
+                'attribute_code' => 'customer_attribute1',
+                'value' => 'customer_attribute1_value'
+            ]),
+            'customer_attribute2' => new AttributeValue([
+                'attribute_code' => 'customer_attribute2',
+                'value' => ['customer_attribute2_value1', 'customer_attribute2_value2']
+            ])
+        ];
+        $model->method('getCustomAttributesCodes')->willReturn(array_keys($data));
+        $this->objectManager->setBackwardCompatibleProperty(
+            $model,
+            'customAttributeFactory',
+            $customAttributeFactory
+        );
+        $model->setData('custom_attributes', $data);
+        $this->assertEquals(
+            [
+                [
+                    'attribute_code' => 'customer_attribute1',
+                    'value' => 'customer_attribute1_value'
+                ],
+                [
+                    'attribute_code' => 'customer_attribute2',
+                    'value' => "customer_attribute2_value1\ncustomer_attribute2_value2"
+                ]
+            ],
+            array_map(
+                fn ($attr) => ['attribute_code' => $attr->getAttributeCode(), 'value' => $attr->getValue()],
+                $model->getCustomAttributes()
+            )
+        );
+    }
+
     protected function tearDown(): void
     {
         $this->objectManager->setBackwardCompatibleProperty(