std.json segmentation fault

[Stephan]

On Monday, 4 February 2013 at 10:04:10 UTC, Andrea Fontana wrote:
> This code was working some months ago:
>
> import std.json;
> JSONValue total;
> total.type = JSON_TYPE.OBJECT;
> total["results"].type = JSON_TYPE.OBJECT;
>
>
> Now, last line gives me a segmentation fault. What's wrong with 
> this code?

Here is a full test case. I don't want to submit it to Bugzilla 
yet, since I don't know whether it's intended behaviour or a bug. 
I have a slight feeling that this is NOT a bug. Somehow, in the 
first case a reference to an invalid struct is returned by 
json["hello"] and attempted to be overridden by a new JSONValue. 
In the second case, no reference is generated, instead a simple 
struct copy (a blit) is invoked, which works. Can someone explain 
this more correctly?

This program crashes (tested on dmd 2.061)
import std.json;
void main() {
   JSONValue json;
   json.type = JSON_TYPE.OBJECT;
   json["hello"] = JSONValue();
}

This program works fine:
import std.json;
void main() {
   JSONValue json;
   json.type = JSON_TYPE.OBJECT;
   json.object["hello"] = JSONValue();
}