Cconditional expression in return statement. Bug?

[Jack Applegame via Digitalmars-d-learn]

Code (https://dpaste.dzfl.pl/8e7a9c380e99):

import std.stdio;
struct Foo {
     int val;
     this(int val) {
         writefln("%s.this(int)", val);
         this.val = val;
     }
     this(this) {
         writefln("%s.this(this)", val);
         this.val = val;
     }
     ~this() {
         writefln("%s.~this()", val);
         this.val = val;
     }
}
struct Bar {
     Foo foo;
     this(Foo foo, bool) { this.foo = foo; }
}

bool fun(bool val) { return !val; }

auto genBar(bool flag) {
     return flag ? Bar() : Bar(Foo(10), fun(!flag));
}

void main(string[] args) {
     auto bar = genBar(args.length == 0);
}

Compiler generates extra destructor call:

10.this(int)
10.this(this)
10.~this()
10.~this()
10.~this()

If we slightly change function genBar:
auto genBar(bool flag) {
     auto a = flag ? Bar() : Bar(Foo(10), fun(!flag));
     return a;
}

or

auto genBar(bool flag) {
     return flag ? Bar() : Bar(Foo(10), false);
}

then output looks as expected:

10.this(int)
10.this(this)
10.~this()
10.~this()

I'm pretty sure this is a bug. And very bad bug. I spent several 
hours looking for it.
What do you think?