MC-36383: [B2B] A Product with Customizable Option (File) can not be added from a Requisition List to the Shopping Cart

Author: SmVladyslav

app/code/Magento/Catalog/Model/Product/Option/Type/File.php

@@ -228,7 +228,10 @@ public function validateUserValue($values)
          * previous configuration with no newly uploaded file
          */
         $fileInfo = null;
-        if (isset($values[$option->getId()]) && is_array($values[$option->getId()])) {
+        if (isset($values[$option->getId()])) {
+            if (is_string($values[$option->getId()])) {
+                $values[$option->getId()] = explode(',', $values[$option->getId()]);
+            }
             // Legacy style, file info comes in array with option id index
             $fileInfo = $values[$option->getId()];
         } else {