MAGETWO-64047: WebAPI: It's impossible to empty numeric fields after they're set

 - fix tests

Author: Cari Spruiell

app/code/Magento/Catalog/Model/Product/Attribute/Backend/Price.php

@@ -128,7 +128,7 @@ public function afterSave($object)
         $attribute = $this->getAttribute();
         $attributeCode = $attribute->getAttributeCode();
         $value = $object->getData($attributeCode);
-        if ($value === null  || (float)$value > 0) {
+        if ($value === null || (float)$value > 0) {
             if ($attribute->isScopeWebsite() && $object->getStoreId() != \Magento\Store\Model\Store::DEFAULT_STORE_ID) {
                 if ($this->isUseDefault($object)) {
                     $value = null;

dev/tests/api-functional/testsuite/Magento/Catalog/Api/ProductRepositoryInterfaceTest.php

@@ -1275,6 +1275,11 @@ public function testSpecialPrice()
      */
     public function testResetSpecialPrice()
     {
+        $this->_markTestAsRestOnly(
+            'In order to properly run this test for SOAP, XML must be used to specify <value></value> ' .
+            'for the special_price value. Otherwise, the null value gets processed as a string and ' .
+            'cast to a double value of 0.0.'
+        );
         $productData = $this->getSimpleProductData();
         $productData['custom_attributes'] = [
             ['attribute_code' => self::KEY_SPECIAL_PRICE, 'value' => 5.00]