crash with variable-size keyed samples

[justme151]

I have a problem with a keyed type that has variable serialized key size.
register_instance can crash after a short key is seen first and a longer key is registered later. I managed to create a minimal repro that demonstrates the issue.

• CycloneDDS-CXX 11.0.1
• OS: Debian

IDL

module repro {
  @final
  struct KeyedSample {
    @key string<255> id;
    int32 value;
  };
};

Minimal C++ program

#include <dds/dds.hpp>
#include <iostream>
#include <string>

#include "repro.hpp"

static repro::KeyedSample makeSample(const std::string& key, int32_t v) {
    repro::KeyedSample s;
    s.id(key);
    s.value(v);
    return s;
}

int main() {
    dds::domain::DomainParticipant participant(0);
    dds::topic::Topic<repro::KeyedSample> topic(participant, "myTopic");
    dds::pub::Publisher publisher(participant);
    dds::pub::DataWriter<repro::KeyedSample> writer(publisher, topic);

    const std::string shortKey = "short";
    const std::string longKey19 = "longkeyabcdefghijkl";  // 19 chars
    const std::string longKey20 = "longkeyabcdefghijklm"; // 20 chars

    writer.register_instance(makeSample(shortKey, 1));
    std::cout << "1. Works" << std::endl;
    writer.register_instance(makeSample(longKey19, 2));
    std::cout << "2. Works" << std::endl;
    writer.register_instance(makeSample(longKey20, 3)); // --> This call segfaults
    std::cout << "Won't print" << std::endl;
    return 0;
}

Steps to reproduce

1. Generate type support from the IDL with idlc.
2. Build the repro program against CycloneDDS-CXX.
3. Run the program.

Result

Can someone confirm that this program crashes with segmentation fault during register_instance after key length crosses boundary in this sequence?

Output:

1. Works
2. Works
Segmentation fault (core dumped)