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free-audio / clap-plugins

MIT License
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plugin asserts when host returns a `clap_host_audio_ports` pointer in call to `clap_host->get_extension()` #5

Open BillyDM opened 2 years ago

BillyDM commented 2 years ago

When my host returns a pointer to a clap_host_audio_ports struct after receiving the "clap.audio-ports" extension id from the plugin in clap_host->get_extension(), then the plugin later asserts with:

/home/billydm/Dev/clap-plugins/clap-helpers/include/clap/helpers/host-proxy.hxx:38: void clap::helpers::HostProxy<h, l>::getExtension(const T*&, const char*) [with T = clap_host_audio_ports; clap::helpers::MisbehaviourHandler h = clap::helpers::MisbehaviourHandler::Terminate; clap::helpers::CheckingLevel l = clap::helpers::CheckingLevel::Maximal]: Assertion `!ptr' failed.

If my host returns a nullptr instead, then the assert does not happen.

Is the assert(!ptr) assert here at line 38 of host-proxy.hxx a bug?

   template <MisbehaviourHandler h, CheckingLevel l>
   template <typename T>
   void HostProxy<h, l>::getExtension(const T *&ptr, const char *id) noexcept {
      assert(!ptr);
      assert(id);

      if (_host->get_extension)
         ptr = static_cast<const T *>(_host->get_extension(_host, id));
   }