This is essentially an extension of https://issues.dlang.org/show_bug.cgi?id=24773

The fix for that one partially fixed the problem, but sort has a lot of branches depending on the types used and the actual set of elements being sorted, and there's another branch that's much harder to hit which also uses uninitializedArray in spite of a type defining opAssign (which it will if the type has a destructor).

The test case that I came up with is

---
void main()
{
    static struct E
    {
        int value;
        int valid = 42;

        ~this()
        {
            assert(valid == 42);
        }
    }

    import std.array : array;
    import std.range : chain, only, repeat;
    auto arr = chain(repeat(E(41), 18),
                     only(E(39)),
                     repeat(E(41), 16),
                     only(E(1)),
                     repeat(E(42), 33),
                     only(E(33)),
                     repeat(E(42), 16),
                     repeat(E(43), 27),
                     only(E(33)),
                     repeat(E(43), 34),
                     only(E(34)),
                     only(E(43)),
                     only(E(63)),
                     repeat(E(44), 42),
                     only(E(27)),
                     repeat(E(44), 11),
                     repeat(E(45), 64),
                     repeat(E(46), 3),
                     only(E(11)),
                     repeat(E(46), 7),
                     only(E(4)),
                     repeat(E(46), 34),
                     only(E(36)),
                     repeat(E(46), 17),
                     repeat(E(47), 36),
                     only(E(39)),
                     repeat(E(47), 26),
                     repeat(E(48), 17),
                     only(E(21)),
                     repeat(E(48), 5),
                     only(E(39)),
                     repeat(E(48), 14),
                     only(E(58)),
                     repeat(E(48), 24),
                     repeat(E(49), 13),
                     only(E(40)),
                     repeat(E(49), 38),
                     only(E(18)),
                     repeat(E(49), 11),
                     repeat(E(50), 6)).array();

    import std.algorithm.mutation : SwapStrategy;
    import std.algorithm.sorting : sort;
    arr.sort!((a, b) => a.value < b.value, SwapStrategy.stable)();
}
---

It's not terribly pretty, and there's probably a shorter list of values which would trigger the problem, but I found it to be quite difficult to purposefully hit the branch that has the problem, and this list of values does it.