Unverified Commit 3d1c34d3 authored by John DiSanti's avatar John DiSanti Committed by GitHub
Browse files

Fix panic from repeat clones of `TypeErasedBox` (#2842) 

This PR fixes a panic that would result from cloning a cloneable
`TypeErasedBox` twice.

----

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parent c1a1daee

rust-runtime/aws-smithy-types/src/config_bag.rs

+7 −0
Original line number Diff line number Diff line
@@ -855,6 +855,13 @@ mod test { 
        layer_1.unset::<TestStr>();

        assert!(layer_1.try_clone().unwrap().load::<TestStr>().is_none());



        // It is cloneable multiple times in succession

        let _ = layer_1

            .try_clone()

            .expect("clone 1")

            .try_clone()

            .expect("clone 2");



        #[derive(Clone, Debug)]

        struct Rope(String);

        impl Storable for Rope {

rust-runtime/aws-smithy-types/src/type_erasure.rs

+13 −4
Original line number Diff line number Diff line
@@ -122,7 +122,13 @@ impl TypeErasedBox { 


impl fmt::Debug for TypeErasedBox {

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

        f.write_str("TypeErasedBox:")?;

        f.write_str("TypeErasedBox[")?;

        if self.clone.is_some() {

            f.write_str("Clone")?;

        } else {

            f.write_str("!Clone")?;

        }

        f.write_str("]:")?;

        (self.debug)(&self.field, f)

    }

}
@@ -145,7 +151,7 @@ impl TypeErasedBox { 
            fmt::Debug::fmt(value.downcast_ref::<T>().expect("type-checked"), f)

        };

        let clone = |value: &Box<dyn Any + Send + Sync>| {

            TypeErasedBox::new(value.downcast_ref::<T>().expect("typechecked").clone())

            TypeErasedBox::new_with_clone(value.downcast_ref::<T>().expect("typechecked").clone())

        };

        Self {

            field: Box::new(value),
@@ -292,8 +298,11 @@ mod tests { 
            .0 = "3";



        let bar_erased = bar.erase();

        assert_eq!("TypeErasedBox:Foo(\"3\")", format!("{foo_erased:?}"));

        assert_eq!("TypeErasedBox:Bar(2)", format!("{bar_erased:?}"));

        assert_eq!(

            "TypeErasedBox[!Clone]:Foo(\"3\")",

            format!("{foo_erased:?}")

        );

        assert_eq!("TypeErasedBox[!Clone]:Bar(2)", format!("{bar_erased:?}"));



        let bar_erased = TypedBox::<Foo>::assume_from(bar_erased).expect_err("it's not a Foo");

        let mut bar = TypedBox::<Bar>::assume_from(bar_erased).expect("it's a Bar");