From 5dd3e5e2bfd1df6e9dda18de508dc1a10cb37e7a Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <contact@guillaume-gomez.fr>
Date: Mon, 4 May 2026 00:05:38 +0200
Subject: [PATCH] Add a `doc_cfg` regression test to ensure foreign types impls
 are working as expected

---
 tests/rustdoc-html/doc-cfg/impl-foreign-type.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 tests/rustdoc-html/doc-cfg/impl-foreign-type.rs

diff --git a/tests/rustdoc-html/doc-cfg/impl-foreign-type.rs b/tests/rustdoc-html/doc-cfg/impl-foreign-type.rs
new file mode 100644
index 0000000000000..e4697c5b8dbef
--- /dev/null
+++ b/tests/rustdoc-html/doc-cfg/impl-foreign-type.rs
@@ -0,0 +1,15 @@
+// This test ensures that the `doc_cfg` feature works on foreign types impl.
+// Regression test for <https://github.com/rust-lang/rust/issues/150268>.
+
+// ignore-tidy-linelength
+
+#![feature(doc_cfg)]
+#![crate_name = "foo"]
+
+//@has 'foo/trait.Blob.html'
+//@has - '//*[@id="impl-Blob-for-Box%3CR%3E"]//*[@class="stab portability"]' 'Available on non-crate feature alloc only.'
+
+pub trait Blob {}
+
+#[cfg(not(feature = "alloc"))]
+impl<R: ?Sized> Blob for std::boxed::Box<R> {}