Is this defined behaviour in D?

[John Burton]

If I have a int* pointer for example, that points to the start of 
an int array and step through the array until I get the value 
123, is it defined in D what happens if you step off the end of 
the array?

What I might expect to happen is for the code to just keep 
stepping through sequential memory locations until it finds one 
that happens to have a 123 in it, until it gets a memory 
protection fault of some kind, or failing that wrap around memory 
and go into an infinite loop.

The options are really
1) I can rely on the compiler consistently doing what I'd 
"expect" on a specific platform.
2) There is some other defined behaviour
3) The compiler can do whatever crazy thing it feels like as this 
is considered broken code.

I'm not for a moment suggesting this is a good idea, but what I'm 
really asking is does the D language say anything about this? C++ 
seems to have chosen (3). Personally I'd prefer (1) but it's most 
to know if the "standard" such as it is has anything to say on 
such matters.