From 908a69213c1bdee89882174162e0445dfd6fc2c5 Mon Sep 17 00:00:00 2001
From: Benoit Blanchon <git@benoitblanchon.fr>
Date: Thu, 26 Jun 2025 15:23:57 +0200
Subject: [PATCH] Fix null data_

---
 src/ArduinoJson/Variant/VariantImpl.hpp | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/ArduinoJson/Variant/VariantImpl.hpp b/src/ArduinoJson/Variant/VariantImpl.hpp
index 17f9f253..c4cece47 100644
--- a/src/ArduinoJson/Variant/VariantImpl.hpp
+++ b/src/ArduinoJson/Variant/VariantImpl.hpp
@@ -19,7 +19,7 @@ inline void VariantImpl::setRawString(SerializedValue<T> value) {
 }
 
 inline bool VariantImpl::setLinkedString(const char* s) {
-  ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
+  ARDUINOJSON_ASSERT(isNull());  // must call clear() first
   ARDUINOJSON_ASSERT(s);
 
   auto slotId = resources_->saveStaticString(s);
@@ -33,7 +33,7 @@ inline bool VariantImpl::setLinkedString(const char* s) {
 
 template <typename TAdaptedString>
 inline bool VariantImpl::setString(TAdaptedString value) {
-  ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
+  ARDUINOJSON_ASSERT(isNull());  // must call clear() first
 
   if (!data_)
     return false;
@@ -90,7 +90,10 @@ inline const char* VariantImpl::asLinkedString() const {
 
 template <typename T>
 enable_if_t<sizeof(T) == 8, bool> VariantImpl::setFloat(T value) {
-  ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
+  ARDUINOJSON_ASSERT(isNull());  // must call clear() first
+
+  if (!data_)
+    return false;
 
   float valueAsFloat = static_cast<float>(value);
 
@@ -115,7 +118,10 @@ enable_if_t<sizeof(T) == 8, bool> VariantImpl::setFloat(T value) {
 
 template <typename T>
 enable_if_t<is_signed<T>::value, bool> VariantImpl::setInteger(T value) {
-  ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
+  ARDUINOJSON_ASSERT(isNull());  // must call clear() first
+
+  if (!data_)
+    return false;
 
   if (canConvertNumber<int32_t>(value)) {
     data_->type = VariantType::Int32;
@@ -136,7 +142,10 @@ enable_if_t<is_signed<T>::value, bool> VariantImpl::setInteger(T value) {
 
 template <typename T>
 enable_if_t<is_unsigned<T>::value, bool> VariantImpl::setInteger(T value) {
-  ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
+  ARDUINOJSON_ASSERT(isNull());  // must call clear() first
+
+  if (!data_)
+    return false;
 
   if (canConvertNumber<uint32_t>(value)) {
     data_->type = VariantType::Uint32;