[type_caster<char>] Support of nullptr from cpp?

[huangweiwu]

When I bind a const char*<> type function, it will crash when returns a nullptr.
Shell we support it in the from_cpp function of [type_caster]?

const char* test_func()
{
    return nullptr;
}
m.def("test_func", test_func);

[wjakob]

Sorry, I saw this just now. That would be reasonable. Could you make a PR?

[huangweiwu]

I have no permission to push to this project currently.

[wjakob]

The way to do it is to create a fork, make changes in a branch, and then open a pull request. If those terms are unclear to you, then please review the documentation of GitHub (I cannot provide that level of support here.)

[huangweiwu]

It's ok now.

[wjakob]

fixed by @huangweiwu in PR #318.