Remember to check the name of the associated type being projected when searching the environment. Fixes #20651.

src/test/compile-fail/associated-types-multiple-types-one-trait.rs

@@ -0,0 +1,56 @@
+// Copyright 2015 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.
+
+trait Foo {
+    type X;
+    type Y;
+}
+
+fn have_x_want_x<T:Foo<X=u32>>(t: &T)
+{
+    want_x(t);
+}
+
+fn have_x_want_y<T:Foo<X=u32>>(t: &T)
+{
+    want_y(t); //~ ERROR type mismatch
+}
+
+fn have_y_want_x<T:Foo<Y=i32>>(t: &T)
+{
+    want_x(t); //~ ERROR type mismatch
+}
+
+fn have_y_want_y<T:Foo<Y=i32>>(t: &T)
+{
+    want_y(t);
+}
+
+fn have_xy_want_x<T:Foo<X=u32,Y=i32>>(t: &T)
+{
+    want_x(t);
+}
+
+fn have_xy_want_y<T:Foo<X=u32,Y=i32>>(t: &T)
+{
+    want_y(t);
+}
+
+fn have_xy_want_xy<T:Foo<X=u32,Y=i32>>(t: &T)
+{
+    want_x(t);
+    want_y(t);
+}
+
+fn want_x<T:Foo<X=u32>>(t: &T) { }
+
+fn want_y<T:Foo<Y=i32>>(t: &T) { }
+
+fn main() { }