diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index 59dcc1ebf..d6bd43a74 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -756,9 +756,14 @@ fn walk_parents<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> (Position, & } else if let Some(trait_id) = cx.tcx.trait_of_item(id) && let arg_ty = cx.tcx.erase_regions(cx.typeck_results().expr_ty_adjusted(e)) && let ty::Ref(_, sub_ty, _) = *arg_ty.kind() - && let subs = cx.typeck_results().node_substs_opt(child_id).unwrap_or_else( - || cx.tcx.mk_substs([].iter()) - ) && let impl_ty = if cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref() { + && let subs = match cx + .typeck_results() + .node_substs_opt(parent.hir_id) + .and_then(|subs| subs.get(1..)) + { + Some(subs) => cx.tcx.mk_substs(subs.iter().copied()), + None => cx.tcx.mk_substs([].iter()), + } && let impl_ty = if cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref() { // Trait methods taking `&self` sub_ty } else { diff --git a/tests/ui/needless_borrow.fixed b/tests/ui/needless_borrow.fixed index cb0051224..09afe2ddb 100644 --- a/tests/ui/needless_borrow.fixed +++ b/tests/ui/needless_borrow.fixed @@ -115,6 +115,18 @@ fn main() { fn foo_ref(&self) {} } (&&()).foo_ref(); // Don't lint. `&()` will call `<() as FooRef>::foo_ref` + + struct S; + impl From for u32 { + fn from(s: S) -> Self { + (&s).into() + } + } + impl From<&S> for u32 { + fn from(s: &S) -> Self { + 0 + } + } } #[allow(clippy::needless_borrowed_reference)] diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs index d636a4010..3ae4722a1 100644 --- a/tests/ui/needless_borrow.rs +++ b/tests/ui/needless_borrow.rs @@ -115,6 +115,18 @@ fn main() { fn foo_ref(&self) {} } (&&()).foo_ref(); // Don't lint. `&()` will call `<() as FooRef>::foo_ref` + + struct S; + impl From for u32 { + fn from(s: S) -> Self { + (&s).into() + } + } + impl From<&S> for u32 { + fn from(s: &S) -> Self { + 0 + } + } } #[allow(clippy::needless_borrowed_reference)]