Removed member call on null

src/ArduinoJson/Collection/CollectionImpl.hpp

@@ -26,7 +26,7 @@ inline VariantSlot* CollectionData::addSlot(MemoryPool* pool) {
 }
 
 inline VariantData* CollectionData::add(MemoryPool* pool) {
-  return addSlot(pool)->data();
+  return slotData(addSlot(pool));
 }
 
 template <typename TAdaptedString>

src/ArduinoJson/Variant/SlotFunctions.hpp

@@ -32,4 +32,8 @@ inline size_t slotSize(const VariantSlot* var) {
   }
   return n;
 }
+
+inline VariantData* slotData(VariantSlot* slot) {
+  return reinterpret_cast<VariantData*>(slot);
+}
 }  // namespace ARDUINOJSON_NAMESPACE