Add test for infinite redirection

Author: GuillaumeGomez

src/test/rustdoc/infinite-redirection.rs

@@ -0,0 +1,29 @@
+#![crate_name = "foo"]
+
+// This test ensures that there is no "infinite redirection" file generated (a
+// file which redirects to itself).
+
+// We check it's not a redirection file.
+// @has 'foo/builders/struct.ActionRowBuilder.html'
+// @has - '//*[@id="synthetic-implementations"]' 'Auto Trait Implementations'
+
+// And that the link in the module is targetting it.
+// @has 'foo/builders/index.html'
+// @has - '//a[@href="struct.ActionRowBuilder.html"]' 'ActionRowBuilder'
+
+mod auto {
+    mod action_row {
+        pub struct ActionRowBuilder;
+    }
+
+    #[doc(hidden)]
+    pub mod builders {
+        pub use super::action_row::ActionRowBuilder;
+    }
+}
+
+pub use auto::*;
+
+pub mod builders {
+    pub use crate::auto::builders::*;
+}