From 519dcc50293c01939ff8b4c63e53111c1d738cc2 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Thu, 15 Jul 2021 20:32:37 +0200
Subject: [PATCH] :bug: fix leak for all types

---
 .../nlohmann/detail/conversions/to_json.hpp   | 22 +++++++++++++++----
 single_include/nlohmann/json.hpp              | 22 +++++++++++++++----
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/include/nlohmann/detail/conversions/to_json.hpp b/include/nlohmann/detail/conversions/to_json.hpp
index a0ca4211a..8d1ac30c5 100644
--- a/include/nlohmann/detail/conversions/to_json.hpp
+++ b/include/nlohmann/detail/conversions/to_json.hpp
@@ -30,6 +30,7 @@ struct external_constructor<value_t::boolean>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::boolean;
         j.m_value = b;
         j.assert_invariant();
@@ -42,6 +43,7 @@ struct external_constructor<value_t::string>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value = s;
         j.assert_invariant();
@@ -50,6 +52,7 @@ struct external_constructor<value_t::string>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value = std::move(s);
         j.assert_invariant();
@@ -60,6 +63,7 @@ struct external_constructor<value_t::string>
                              int > = 0 >
     static void construct(BasicJsonType& j, const CompatibleStringType& str)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value.string = j.template create<typename BasicJsonType::string_t>(str);
         j.assert_invariant();
@@ -72,6 +76,7 @@ struct external_constructor<value_t::binary>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::binary_t& b)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::binary;
         j.m_value = typename BasicJsonType::binary_t(b);
         j.assert_invariant();
@@ -80,6 +85,7 @@ struct external_constructor<value_t::binary>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::binary_t&& b)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::binary;
         j.m_value = typename BasicJsonType::binary_t(std::move(b));;
         j.assert_invariant();
@@ -92,6 +98,7 @@ struct external_constructor<value_t::number_float>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_float;
         j.m_value = val;
         j.assert_invariant();
@@ -104,6 +111,7 @@ struct external_constructor<value_t::number_unsigned>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_unsigned;
         j.m_value = val;
         j.assert_invariant();
@@ -116,6 +124,7 @@ struct external_constructor<value_t::number_integer>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_integer;
         j.m_value = val;
         j.assert_invariant();
@@ -128,6 +137,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = arr;
         j.set_parents();
@@ -137,6 +147,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = std::move(arr);
         j.set_parents();
@@ -150,6 +161,8 @@ struct external_constructor<value_t::array>
     {
         using std::begin;
         using std::end;
+
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value.array = j.template create<typename BasicJsonType::array_t>(begin(arr), end(arr));
         j.set_parents();
@@ -159,6 +172,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const std::vector<bool>& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = value_t::array;
         j.m_value.array->reserve(arr.size());
@@ -174,6 +188,7 @@ struct external_constructor<value_t::array>
              enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
     static void construct(BasicJsonType& j, const std::valarray<T>& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = value_t::array;
         j.m_value.array->resize(arr.size());
@@ -192,6 +207,7 @@ struct external_constructor<value_t::object>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value = obj;
         j.set_parents();
@@ -201,6 +217,7 @@ struct external_constructor<value_t::object>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value = std::move(obj);
         j.set_parents();
@@ -214,6 +231,7 @@ struct external_constructor<value_t::object>
         using std::begin;
         using std::end;
 
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value.object = j.template create<typename BasicJsonType::object_t>(begin(obj), end(obj));
         j.set_parents();
@@ -236,10 +254,6 @@ template<typename BasicJsonType, typename CompatibleString,
          enable_if_t<std::is_constructible<typename BasicJsonType::string_t, CompatibleString>::value, int> = 0>
 void to_json(BasicJsonType& j, const CompatibleString& s)
 {
-    if (!j.is_null())
-    {
-        j = BasicJsonType();
-    }
     external_constructor<value_t::string>::construct(j, s);
 }
 
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index cc7195447..58d4305e0 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -4497,6 +4497,7 @@ struct external_constructor<value_t::boolean>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::boolean;
         j.m_value = b;
         j.assert_invariant();
@@ -4509,6 +4510,7 @@ struct external_constructor<value_t::string>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value = s;
         j.assert_invariant();
@@ -4517,6 +4519,7 @@ struct external_constructor<value_t::string>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value = std::move(s);
         j.assert_invariant();
@@ -4527,6 +4530,7 @@ struct external_constructor<value_t::string>
                              int > = 0 >
     static void construct(BasicJsonType& j, const CompatibleStringType& str)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::string;
         j.m_value.string = j.template create<typename BasicJsonType::string_t>(str);
         j.assert_invariant();
@@ -4539,6 +4543,7 @@ struct external_constructor<value_t::binary>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::binary_t& b)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::binary;
         j.m_value = typename BasicJsonType::binary_t(b);
         j.assert_invariant();
@@ -4547,6 +4552,7 @@ struct external_constructor<value_t::binary>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::binary_t&& b)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::binary;
         j.m_value = typename BasicJsonType::binary_t(std::move(b));;
         j.assert_invariant();
@@ -4559,6 +4565,7 @@ struct external_constructor<value_t::number_float>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_float;
         j.m_value = val;
         j.assert_invariant();
@@ -4571,6 +4578,7 @@ struct external_constructor<value_t::number_unsigned>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_unsigned;
         j.m_value = val;
         j.assert_invariant();
@@ -4583,6 +4591,7 @@ struct external_constructor<value_t::number_integer>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::number_integer;
         j.m_value = val;
         j.assert_invariant();
@@ -4595,6 +4604,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = arr;
         j.set_parents();
@@ -4604,6 +4614,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = std::move(arr);
         j.set_parents();
@@ -4617,6 +4628,8 @@ struct external_constructor<value_t::array>
     {
         using std::begin;
         using std::end;
+
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value.array = j.template create<typename BasicJsonType::array_t>(begin(arr), end(arr));
         j.set_parents();
@@ -4626,6 +4639,7 @@ struct external_constructor<value_t::array>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const std::vector<bool>& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = value_t::array;
         j.m_value.array->reserve(arr.size());
@@ -4641,6 +4655,7 @@ struct external_constructor<value_t::array>
              enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
     static void construct(BasicJsonType& j, const std::valarray<T>& arr)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::array;
         j.m_value = value_t::array;
         j.m_value.array->resize(arr.size());
@@ -4659,6 +4674,7 @@ struct external_constructor<value_t::object>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value = obj;
         j.set_parents();
@@ -4668,6 +4684,7 @@ struct external_constructor<value_t::object>
     template<typename BasicJsonType>
     static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
     {
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value = std::move(obj);
         j.set_parents();
@@ -4681,6 +4698,7 @@ struct external_constructor<value_t::object>
         using std::begin;
         using std::end;
 
+        j.m_value.destroy(j.m_type);
         j.m_type = value_t::object;
         j.m_value.object = j.template create<typename BasicJsonType::object_t>(begin(obj), end(obj));
         j.set_parents();
@@ -4703,10 +4721,6 @@ template<typename BasicJsonType, typename CompatibleString,
          enable_if_t<std::is_constructible<typename BasicJsonType::string_t, CompatibleString>::value, int> = 0>
 void to_json(BasicJsonType& j, const CompatibleString& s)
 {
-    if (!j.is_null())
-    {
-        j = BasicJsonType();
-    }
     external_constructor<value_t::string>::construct(j, s);
 }