https://issues.dlang.org/show_bug.cgi?id=23440

Steven Schveighoffer <schveiguy@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |safe
                 CC|                            |schveiguy@gmail.com

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https://issues.dlang.org/show_bug.cgi?id=23440

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://issues.dlang.org/sh
                   |                            |ow_bug.cgi?id=23445

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https://issues.dlang.org/show_bug.cgi?id=23440

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P3

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https://issues.dlang.org/show_bug.cgi?id=23440

kinke <kinke@gmx.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kinke@gmx.net
           Severity|normal                      |critical

--- Comment #1 from kinke <kinke@gmx.net> ---
Just hit this too. Bumping priority to critical.

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https://issues.dlang.org/show_bug.cgi?id=23440

Steven Schveighoffer <schveiguy@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid

--- Comment #2 from Steven Schveighoffer <schveiguy@gmail.com> ---
The closure should fail to allocate, since it has to point at scope data from the heap.

It can be reduced to this case:

```d
@safe:
auto foo(scope int *x)
{
    return { return x; };
}

auto bar() {
    int x = 5;
    return foo(&x);
}

void smash() {
    ubyte[1024] data;
}
void main()
{
    import std.stdio;
    auto dg = bar();
    smash();
    writeln(*dg());
}
```

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https://issues.dlang.org/show_bug.cgi?id=23440

Ate Eskola <Ajieskola@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Ajieskola@gmail.com

--- Comment #3 from Ate Eskola <Ajieskola@gmail.com> ---
This isn't due to any bug in variadic arrays. They are (as far as I tested) properly treated as `scope` arrays with the `-preview=dip1000` flag.

The real failure is in creation of the closure. This compiles and behaves exactly like the original example:

---
void delegate() @safe foo(scope int[] stuff) @safe {
        return () {
                assert(stuff == [1,2,3]);
                foreach(item; stuff) {}
        };
}

void delegate() @safe helper() @safe {
        int[3] stArray = [1, 2, 3];
        return foo(stArray);
}

void bar() @safe {
        int[2048] pwned; // just to smash the stack
}

void main() @safe {
        auto dg = helper();
        bar();
        dg();
}
---

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https://issues.dlang.org/show_bug.cgi?id=23440

--- Comment #4 from RazvanN <razvan.nitu1305@gmail.com> ---
*** Issue 23813 has been marked as a duplicate of this issue. ***

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https://issues.dlang.org/show_bug.cgi?id=23440

--- Comment #5 from Adam D. Ruppe <destructionator@gmail.com> ---
user on the discord posted this which also seems kinda similar


import std;


auto makeClosure(ref int n) @safe
{
    return ref () => n;
}

auto escapeClosure() @safe
{
    int n = 123;
    return makeClosure(n);
}

void clobberStack() @safe
{
    ubyte[4096] a;
}

void main() @safe
{
    auto dg = escapeClosure();
    pragma(msg,typeof(dg));
    clobberStack();
    assert(dg() == 123); // kaboom
}

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