tests: Move run-pass tests without naming conflicts to ui

src/test/ui/uniform-paths/basic-nested.rs

@@ -0,0 +1,61 @@
+// This test is similar to `basic.rs`, but nested in modules.
+
+// run-pass
+// edition:2018
+
+#![feature(decl_macro)]
+
+#![allow(unused_imports)]
+#![allow(non_camel_case_types)]
+
+mod foo {
+    // Test that ambiguity errors are not emitted between `self::test` and
+    // `::test`, assuming the latter (crate) is not in `extern_prelude`.
+    mod test {
+        pub struct Foo(pub ());
+    }
+    pub use test::Foo;
+
+    // Test that qualified paths can refer to both the external crate and local item.
+    mod std {
+        pub struct io(pub ());
+    }
+    pub use ::std::io as std_io;
+    pub use self::std::io as local_io;
+}
+
+// Test that we can refer to the external crate unqualified
+// (when there isn't a local item with the same name).
+use std::io;
+
+mod bar {
+    // Also test the unqualified external crate import in a nested module,
+    // to show that the above import doesn't resolve through a local `std`
+    // item, e.g., the automatically injected `extern crate std;`, which in
+    // the Rust 2018 should no longer be visible through `crate::std`.
+    pub use std::io;
+
+    // Also test that items named `std` in other namespaces don't
+    // cause ambiguity errors for the import from `std` above.
+    pub fn std() {}
+    pub macro std() {}
+}
+
+
+fn main() {
+    foo::Foo(());
+    foo::std_io::stdout();
+    foo::local_io(());
+    io::stdout();
+    bar::io::stdout();
+    bar::std();
+    bar::std!();
+
+    {
+        // Test that having `io` in a module scope and a non-module
+        // scope is allowed, when both resolve to the same definition.
+        use std::io;
+        use io::stdout;
+        stdout();
+    }
+}