Uninitialized error string crashes Modipulate

[hryx]

The new fade function was crashing Modipulate after I added error code returns for bad parameters. I think it's because calling modipulate_get_last_error_string crashes unless modipulate_set_error_string_cpp has been called at least once.

(I fixed it in this case by setting the error string before returning an error code.)

Maybe we should initialize the error string?

[MrEricSir]

Counter-proposal: We create an error macro that looks kinda like this:

RETURN_ERROR("Your error string here!", ERROR_WILL_ROBINSON);

The macro takes a string and an int. It sets the error string and returns with the provided return code, setting a precedent for all code going forward to include both a string and an error.

[hryx]

👍 That seems reasonable.