add test for --extern-html-root-url

Author: QuietMisdreavus

Diff for: src/test/rustdoc/extern-html-root-url.rs

@@ -0,0 +1,18 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+
+// compile-flags:-Z unstable-options --extern-html-root-url core=https://example.com/core/0.1.0
+
+// @has extern_html_root_url/index.html
+// @has - '//a/@href' 'https://example.com/core/0.1.0/core/iter/index.html'
+#[doc(no_inline)]
+pub use std::iter;