Prevent duplicated key generation when serializing lights + RapidJSON backend. Fixes #420

README.md

@@ -197,6 +197,18 @@ if (!ret) {
 * `TINYGLTF_USE_RAPIDJSON` : Use RapidJSON as a JSON parser/serializer. RapidJSON files are not included in TinyGLTF repo. Please set an include path to RapidJSON if you enable this feature.
 * `TINYGLTF_USE_CPP14` : Use C++14 feature(requires C++14 compiler). This may give better performance than C++11.
 
+### Wuffs image loader option(faster and secure JPEG/PNG deocoding)
+
+You can use `wuffs` image loader to load JPEG and PNG in fast and securely.
+(`stb_image` has some security issues, whereas `wuffs` is well fuzz tested)
+
+Not that some uncommon JPEG format is unsupported in `wuffs` `std/jpeg` decoder.
+
+* `TINYGLTF_USE_WUFFS_IMAGE_LOADER` : Use `wuffs` to load images. `stb_image` related stuff will be disabled.
+  * `TINYGLTF_NO_STB_IMAGE` supercedes `wuffs` macros. i.e. when `TINYGLTF_NO_STB_IMAGE` is defined, both `stb_image` and `wuffs` are disabled.
+* `TINYGLTF_NO_WUFFS_IMPLEMENTATION` : Do not define `WUFFS_IMPLEMENTATION` inside `tiny_gltf.h`. Define this macro if you use `wuffs` in another C/C++ file.
+
+
 ## CMake options
 
 You can add tinygltf using `add_subdirectory` feature.

tiny_gltf.h

@@ -6767,7 +6767,16 @@ void JsonAddMember(detail::json &o, const char *key, detail::json &&value) {
   if (!o.IsObject()) {
     o.SetObject();
   }
-  o.AddMember(detail::json(key, detail::GetAllocator()), std::move(value), detail::GetAllocator());
+
+  // Issue 420.
+  // AddMember may create duplicated key, so use [] API when a key already exists.
+  // https://github.com/Tencent/rapidjson/issues/771#issuecomment-254386863
+  detail::json_const_iterator it;
+  if (detail::FindMember(o, key, it)) {
+    o[key] = std::move(value); // replace
+  } else {
+    o.AddMember(detail::json(key, detail::GetAllocator()), std::move(value), detail::GetAllocator());
+  }
 #else
   o[key] = std::move(value);
 #endif