MAGETWO-62168: Improve field data converter logging and error reporting

Author: slopukhov

app/code/Magento/Sales/Setup/SerializedDataConverter.php

@@ -37,7 +37,7 @@ public function convert($value)
         }
         if (isset($valueUnserialized['bundle_selection_attributes'])) {
             $valueUnserialized['bundle_selection_attributes'] = parent::convert(
-                    $valueUnserialized['bundle_selection_attributes']
+                $valueUnserialized['bundle_selection_attributes']
             );
         }
         return $this->encodeJson($valueUnserialized);

lib/internal/Magento/Framework/DB/DataConverter/SerializedToJson.php

@@ -84,7 +84,7 @@ protected function unserializeValue($value)
                 $value = $this->serialize->unserialize($value);
             } else {
                 set_error_handler(function ($errorNumber, $errorString) {
-                    throw new DataConversionException($errorString);
+                    throw new DataConversionException($errorString, $errorNumber);
                 });
                 $value = $this->serialize->unserialize($value);
                 restore_error_handler();