[BUG] [C++] [Restbed] Post handler cannot fetch large request Body

Description

I got a generated server with cpp-restbed-generator, and i tried to implement all my endpoints by following this example :

#include "api/PetApi.h"

using namespace org::openapitools::server::api;
using namespace org::openapitools::server::api::PetApiResources;

   
int main() {
    auto service = std::make_shared<restbed::Service>();

    PetsApi petsApi(service);

    petsApi.getPetsResource()->handler_POST_func = [](Pet& pet) {

        return 200; // OK
    };

    auto settings = std::make_shared<restbed::Settings>();
    settings->set_port(8080);

    service->start(settings);
    return 0;
}

I also tried to create my own Resource and override handler_POST.

I extend the Pet model, and when I send a request to the the POST endpoint with a larger parameter, an error occurred :

I think I have found out which part of the code trigger this error :

in the generated file PetApi.cpp :

the function extractBodyContent() called in handler_POST_internal :

extractBodyContent() :

When the request body of the request is short, extractBodyContent() return a valid value containing the request body, but in the case of a request Body more larger, extractBodyContent() return a null value which trigger the error.

Can you help me to fix this bug ?

openapi-generator version

Generator version : 6.6.0

OpenAPI declaration file content or url

https://github.com/OAI/OpenAPI-Specification/blob/main/examples/v3.0/petstore.yaml

I just modified the pet model:

I changed the name to names in purpose to be able to send larger POST data

Start with the generated PetApi.cpp and inspect handler_POST_internal and the extractBodyContent() call shown in the report. Reproduce the issue using the modified petstore.yaml and a large POST body, comparing it with a short body. Done means the generated Restbed POST handler can retrieve and process the larger request body without returning null.