February 16, 2019
https://issues.dlang.org/show_bug.cgi?id=19680

          Issue ID: 19680
           Summary: [REG2.085.0-beta.1] Uda inside union breaks default
                    initialization
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: zero@vec4.xyz

Code:
----
struct MyInnerStruct {
    union {
        @("BRAKE_ME") int[2] v = 0;
        struct { int x, y; }
    }

    this(int vx, int vy) {
        x = vx; y = vy;
    }
}


struct MyStruct {
    MyInnerStruct inner = MyInnerStruct(1, 2);
}


void main()
{
    {
        MyStruct ok = MyStruct();
        assert(ok.inner.v == [1, 2]);
    }

    {
        MyStruct err;
        assert(err.inner.v == [1, 2]);
    }
}
---


run.dlang.io:
https://run.dlang.io/is/fzj0IM

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