Add regression test for rust-lang#111064

Author: GuillaumeGomez

tests/rustdoc/issue-111064-reexport-trait-from-hidden-2.rs

@@ -0,0 +1,31 @@
+#![feature(no_core)]
+#![no_core]
+#![crate_name = "foo"]
+
+// @!has 'foo/hidden/index.html'
+// FIXME: add missing `@` for the two next tests once issue is fixed!
+// To be done in <https://github.com/rust-lang/rust/issues/111249>.
+// !has 'foo/hidden/inner/index.html'
+// !has 'foo/hidden/inner/trait.Foo.html'
+#[doc(hidden)]
+pub mod hidden {
+    pub mod inner {
+        pub trait Foo {
+            /// Hello, world!
+            fn test();
+        }
+    }
+}
+
+// @has 'foo/visible/index.html'
+// @has 'foo/visible/trait.Foo.html'
+#[doc(inline)]
+pub use hidden::inner as visible;
+
+// @has 'foo/struct.Bar.html'
+// @count - '//*[@id="impl-Foo-for-Bar"]' 1
+pub struct Bar;
+
+impl visible::Foo for Bar {
+    fn test() {}
+}

tests/rustdoc/issue-111064-reexport-trait-from-hidden.rs

@@ -0,0 +1,21 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/111064>.
+// Methods from a re-exported trait inside a `#[doc(hidden)]` item should
+// be visible.
+
+#![crate_name = "foo"]
+
+// @has 'foo/index.html'
+// @has - '//*[@id="main-content"]//*[@class="item-name"]/a[@href="trait.Foo.html"]' 'Foo'
+
+// @has 'foo/trait.Foo.html'
+// @has - '//*[@id="main-content"]//*[@class="code-header"]' 'fn test()'
+
+#[doc(hidden)]
+mod hidden {
+    pub trait Foo {
+        /// Hello, world!
+        fn test();
+    }
+}
+
+pub use hidden::Foo;