From 15ab2ff55adbacb263190f74aba8735c129db420 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Sat, 21 Dec 2024 21:09:40 +0100
Subject: [PATCH] use the correct `ParamEnv` when checking future's return type
 in `missing_errors_doc`

---
 clippy_lints/src/doc/missing_headers.rs | 11 +++++++++--
 tests/ui/crashes/ice-13862.rs           | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 tests/ui/crashes/ice-13862.rs

diff --git a/clippy_lints/src/doc/missing_headers.rs b/clippy_lints/src/doc/missing_headers.rs
index 40377dd841e0..3e2b7055de4d 100644
--- a/clippy_lints/src/doc/missing_headers.rs
+++ b/clippy_lints/src/doc/missing_headers.rs
@@ -1,6 +1,6 @@
 use super::{DocHeaders, MISSING_ERRORS_DOC, MISSING_PANICS_DOC, MISSING_SAFETY_DOC, UNNECESSARY_SAFETY_DOC};
 use clippy_utils::diagnostics::{span_lint, span_lint_and_note};
-use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::ty::{implements_trait_with_env, is_type_diagnostic_item};
 use clippy_utils::{is_doc_hidden, return_ty};
 use rustc_hir::{BodyId, FnSig, OwnerId, Safety};
 use rustc_lint::LateContext;
@@ -70,7 +70,14 @@ pub fn check(
             && let typeck = cx.tcx.typeck_body(body_id)
             && let body = cx.tcx.hir().body(body_id)
             && let ret_ty = typeck.expr_ty(body.value)
-            && implements_trait(cx, ret_ty, future, &[])
+            && implements_trait_with_env(
+                cx.tcx,
+                ty::TypingEnv::non_body_analysis(cx.tcx, owner_id.def_id),
+                ret_ty,
+                future,
+                Some(owner_id.def_id.to_def_id()),
+                &[],
+            )
             && let ty::Coroutine(_, subs) = ret_ty.kind()
             && is_type_diagnostic_item(cx, subs.as_coroutine().return_ty(), sym::Result)
         {
diff --git a/tests/ui/crashes/ice-13862.rs b/tests/ui/crashes/ice-13862.rs
new file mode 100644
index 000000000000..a5f010054b2f
--- /dev/null
+++ b/tests/ui/crashes/ice-13862.rs
@@ -0,0 +1,19 @@
+#![crate_type = "lib"]
+#![no_std]
+
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+pub struct S<const N: u8>;
+
+impl<const N: u8> Future for S<N> {
+    type Output = ();
+    fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> {
+        todo!()
+    }
+}
+
+pub fn f<const N: u8>() -> S<N> {
+    S
+}