Declaring a D pointer to a C function

[Andrej Mitrovic]

I just had a bug where a D function is implicitly converted to an
extern(C) function pointer.

I've had this definition:
alias extern (C) void function(void* userData) PaStreamFinishedCallback;

And this extern(C) function:
PaError  Pa_SetStreamFinishedCallback(PaStream* stream,
PaStreamFinishedCallback streamFinishedCallback);

And I used this callback:
void StreamFinished(void* userData)
{
    auto localData = cast(TestData*)userData;
    writefln("Stream Completed: %s", localData.message);
}

// this is where the binding takes place
void main() { ...; SetStreamFinishedCallback(..., &StreamFinished); }

That code is invalid. The fix is to add extern(C) to my callback:
extern(C) void StreamFinished(void* userData)

Is this going to be fixed any time soon? Allowing callbacks with D
calling convention where a C callback is expected should be an error,
and this is like the 10th time I've ran into this bug.