fix showing help.html from docs

src/web/routes.rs

@@ -328,6 +328,10 @@ pub(super) fn build_axum_routes() -> AxumRouter {
             "/:name/:version/all.html",
             get_rustdoc(super::rustdoc::rustdoc_html_server_handler),
         )
+        .route(
+            "/:name/:version/help.html",
+            get_rustdoc(super::rustdoc::rustdoc_html_server_handler),
+        )
         .route(
             "/:name/:version/settings.html",
             get_rustdoc(super::rustdoc::rustdoc_html_server_handler),

src/web/rustdoc.rs

@@ -966,6 +966,29 @@ mod test {
             .with_context(|| anyhow::anyhow!("no redirect found for {}", path))
     }
 
+    #[test_case(true)]
+    #[test_case(false)]
+    // https://github.com/rust-lang/docs.rs/issues/2313
+    fn help_html(archive_storage: bool) {
+        wrapper(|env| {
+            env.fake_release()
+                .name("krate")
+                .version("0.1.0")
+                .archive_storage(archive_storage)
+                .rustdoc_file("help.html")
+                .create()?;
+            let web = env.frontend();
+            assert_success_cached("/", web, CachePolicy::NoCaching, &env.config())?;
+            assert_success_cached(
+                "/krate/0.1.0/help.html",
+                web,
+                CachePolicy::ForeverInCdnAndStaleInBrowser,
+                &env.config(),
+            )?;
+            Ok(())
+        });
+    }
+
     #[test_case(true)]
     #[test_case(false)]
     // regression test for https://github.com/rust-lang/docs.rs/issues/552