Extract addElement() NO CHANGE

Author: bblanchon

src/ArduinoJson/Variant/VariantData.hpp

@@ -111,7 +111,15 @@ class VariantImpl {
                                                ResourceManager* resources_);
 
   VariantData* addElement() {
-    auto array = isNull() ? toArray() : asArray();
+    return addElement(data_, resources_);
+  }
+
+  static VariantData* addElement(VariantData* data_,
+                                 ResourceManager* resources_) {
+    if (!data_)
+      return nullptr;
+    auto array = data_->type == VariantType::Null ? toArray(data_, resources_)
+                                                  : asArray(data_, resources_);
     return array.addElement();
   }