Nested function bug?

[Ed McCardell]

I ran into a strange and hard-to-describe problem with nested functions 
closing over the argument to their enclosing function.

When a nested function (A) returns the value of another nested function 
(B) that returns a parameter of the enclosing function (C), and when (A) 
is returned from (C), then calling (A) returns an incorrect value if (A) 
has a parameter of class type (it works when (A) has no class parameters).

The code below demonstrates this (using DMD 2.058, no optimizations). Is 
this a bug?


auto foo(T)(int val)
{
     int nested()
     {
         return val;
     }

     int escaping(T ignored)
     {
         return nested();
     }

     return &escaping;

//    return &nested; // this works
}

struct Bar {}

class Baz {}

void main()
{
     auto func1 = foo!int(55);
     auto val1 = func1(12);
     assert(val1 == 55); // works fine with integral type

     auto func2 = foo!Bar(55);
     Bar bar;
     auto val2 = func2(bar);
     assert(val2 == 55); // works fine with struct

     auto func3 = foo!Baz(55);
     auto baz = new Baz();
     auto val3 = func3(baz);
     assert(val3 == 55); // fails; val3 is different value on each run
}