From 7cd48fc3b92c67d3d99257e3d302a931acd966a1 Mon Sep 17 00:00:00 2001
From: Ravi Chandra <ravi.chandra@krishtechnolabs.com>
Date: Fri, 5 Apr 2019 10:30:36 +0530
Subject: [PATCH 1/3] Fixed Changing sample for downloadable product failure

---
 app/code/Magento/Downloadable/Model/SampleRepository.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/app/code/Magento/Downloadable/Model/SampleRepository.php b/app/code/Magento/Downloadable/Model/SampleRepository.php
index 0c7d2b96f1b53..98af48d1df993 100644
--- a/app/code/Magento/Downloadable/Model/SampleRepository.php
+++ b/app/code/Magento/Downloadable/Model/SampleRepository.php
@@ -308,8 +308,11 @@ protected function updateSample(
             $existingSample->setTitle($sample->getTitle());
         }
 
-        if ($sample->getSampleType() === 'file' && $sample->getSampleFileContent() === null) {
-            $sample->setSampleFile($existingSample->getSampleFile());
+        if ($sample->getSampleType() === 'file'
+            && $sample->getSampleFileContent() === null
+            && $sample->getSampleFile() !== null
+        ) {
+            $existingSample->setSampleFile($sample->getSampleFile());
         }
         $this->saveSample($product, $sample, $isGlobalScopeContent);
         return $existingSample->getId();

From b39550ae4e947da335cea2e836005fc000b0082a Mon Sep 17 00:00:00 2001
From: Pavel Bystritsky <p.bystritsky@yandex.ru>
Date: Fri, 12 Apr 2019 15:14:39 +0300
Subject: [PATCH 2/3] magento/magento2#/19806: Static test fix.

---
 app/code/Magento/Downloadable/Model/SampleRepository.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/app/code/Magento/Downloadable/Model/SampleRepository.php b/app/code/Magento/Downloadable/Model/SampleRepository.php
index 98af48d1df993..07c7631fade13 100644
--- a/app/code/Magento/Downloadable/Model/SampleRepository.php
+++ b/app/code/Magento/Downloadable/Model/SampleRepository.php
@@ -23,6 +23,7 @@
 
 /**
  * Class SampleRepository
+ *
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
 class SampleRepository implements \Magento\Downloadable\Api\SampleRepositoryInterface
@@ -100,7 +101,7 @@ public function __construct(
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function getList($sku)
     {
@@ -209,6 +210,8 @@ public function save(
     }
 
     /**
+     * Save sample.
+     *
      * @param \Magento\Catalog\Api\Data\ProductInterface $product
      * @param SampleInterface $sample
      * @param bool $isGlobalScopeContent
@@ -257,6 +260,8 @@ protected function saveSample(
     }
 
     /**
+     * Update sample.
+     *
      * @param \Magento\Catalog\Api\Data\ProductInterface $product
      * @param SampleInterface $sample
      * @param bool $isGlobalScopeContent
@@ -319,7 +324,7 @@ protected function updateSample(
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function delete($id)
     {

From d598262302bc6852cd05020c5013dd38281bfc03 Mon Sep 17 00:00:00 2001
From: Pavel Bystritsky <p.bystritsky@yandex.ru>
Date: Wed, 17 Apr 2019 17:21:10 +0300
Subject: [PATCH 3/3] magento/magento2#19806: Web-Api test fix.

---
 .../Magento/Downloadable/Api/ProductRepositoryTest.php      | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dev/tests/api-functional/testsuite/Magento/Downloadable/Api/ProductRepositoryTest.php b/dev/tests/api-functional/testsuite/Magento/Downloadable/Api/ProductRepositoryTest.php
index 4608b255459b6..d0cace993a24a 100644
--- a/dev/tests/api-functional/testsuite/Magento/Downloadable/Api/ProductRepositoryTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/Downloadable/Api/ProductRepositoryTest.php
@@ -472,6 +472,10 @@ public function testUpdateDownloadableProductSamplesWithNewFile()
             'title' => 'sample2_updated',
             'sort_order' => 2,
             'sample_type' => 'file',
+            'sample_file_content' => [
+                'name' => 'sample2.jpg',
+                'file_data' => base64_encode(file_get_contents($this->testImagePath)),
+            ],
         ];
 
         $response[ExtensibleDataInterface::EXTENSION_ATTRIBUTES_KEY]["downloadable_product_samples"] =
@@ -606,7 +610,7 @@ protected function deleteProductBySku($productSku)
     protected function saveProduct($product)
     {
         if (isset($product['custom_attributes'])) {
-            for ($i=0; $i<sizeof($product['custom_attributes']); $i++) {
+            for ($i = 0, $iMax = count($product['custom_attributes']); $i < $iMax; $i++) {
                 if ($product['custom_attributes'][$i]['attribute_code'] == 'category_ids'
                     && !is_array($product['custom_attributes'][$i]['value'])
                 ) {