A test case for a bug I found in the new SVH while reviewing it.

Namely: non-pub `use` declarations *are* significant to the SVH
computation, since they can change which traits are part of the method
resolution step, and thus affect which methods get called from the
(potentially inlined) code.

Author: pnkfelix

src/test/auxiliary/svh-uta-base.rs

@@ -0,0 +1,32 @@
+// Copyright 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.
+
+//! "compile-fail/svh-uta-trait.rs" is checking that we detect a
+//! change from `use foo::TraitB` to use `foo::TraitB` in the hash
+//! (SVH) computation (#14132), since that will affect method
+//! resolution.
+//!
+//! This is the upstream crate.
+
+#![crate_id = "uta"]
+
+mod traits {
+    pub trait TraitA { fn val(&self) -> int { 2 } }
+    pub trait TraitB { fn val(&self) -> int { 3 } }
+}
+
+impl traits::TraitA for () {}
+impl traits::TraitB for () {}
+
+pub fn foo<T>(_: int) -> int {
+    use traits::TraitA;
+    let v = ();
+    v.val()
+}

src/test/auxiliary/svh-uta-change-use-trait.rs

@@ -0,0 +1,32 @@
+// Copyright 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.
+
+//! "compile-fail/svh-uta-trait.rs" is checking that we detect a
+//! change from `use foo::TraitB` to use `foo::TraitB` in the hash
+//! (SVH) computation (#14132), since that will affect method
+//! resolution.
+//!
+//! This is the upstream crate.
+
+#![crate_id = "uta"]
+
+mod traits {
+    pub trait TraitA { fn val(&self) -> int { 2 } }
+    pub trait TraitB { fn val(&self) -> int { 3 } }
+}
+
+impl traits::TraitA for () {}
+impl traits::TraitB for () {}
+
+pub fn foo<T>(_: int) -> int {
+    use traits::TraitB;
+    let v = ();
+    v.val()
+}

src/test/auxiliary/svh-utb.rs

@@ -0,0 +1,22 @@
+// Copyright 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.
+
+//! "compile-fail/svh-uta-trait.rs" is checking that we detect a
+//! change from `use foo::TraitB` to use `foo::TraitB` in the hash
+//! (SVH) computation (#14132), since that will affect method
+//! resolution.
+//!
+//! This is the downstream crate.
+
+#![crate_id = "utb"]
+
+extern crate uta;
+
+pub fn foo() { assert_eq!(uta::foo::<()>(0), 3); }

src/test/compile-fail/svh-use-trait.rs

@@ -0,0 +1,27 @@
+// Copyright 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.
+
+// note that these aux-build directives must be in this order
+// aux-build:svh-uta-base.rs
+// aux-build:svh-utb.rs
+// aux-build:svh-uta-change-use-trait.rs
+
+//! "compile-fail/svh-uta-trait.rs" is checking that we detect a
+//! change from `use foo::TraitB` to use `foo::TraitB` in the hash
+//! (SVH) computation (#14132), since that will affect method
+//! resolution.
+
+extern crate uta;
+extern crate utb; //~ ERROR: found possibly newer version of crate `uta` which `utb` depends
+//~^ NOTE: perhaps this crate needs to be recompiled
+
+fn main() {
+    utb::foo()
+}