rustc: Fix enum variant privacy across crates

src/librustc/middle/resolve.rs

@@ -1620,18 +1620,20 @@ impl<'a> Resolver<'a> {
 
         match def {
           DefMod(_) | DefForeignMod(_) => {}
-          DefVariant(_, variant_id, is_struct) => {
+          DefVariant(enum_did, variant_id, is_struct) => {
             debug!("(building reduced graph for external crate) building \
                     variant {}",
                    final_ident);
-            // We assume the parent is visible, or else we wouldn't have seen
-            // it. Also variants are public-by-default if the parent was also
-            // public.
+            // If this variant is public, then it was publicly reexported,
+            // otherwise we need to inherit the visibility of the enum
+            // definition.
+            let is_exported = is_public ||
+                              self.external_exports.contains(&enum_did);
             if is_struct {
-                child_name_bindings.define_type(def, DUMMY_SP, true);
+                child_name_bindings.define_type(def, DUMMY_SP, is_exported);
                 self.structs.insert(variant_id);
             } else {
-                child_name_bindings.define_value(def, DUMMY_SP, true);
+                child_name_bindings.define_value(def, DUMMY_SP, is_exported);
             }
           }
           DefFn(..) | DefStaticMethod(..) | DefStatic(..) => {

src/test/auxiliary/issue-11680.rs

@@ -0,0 +1,19 @@
+// 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.
+
+enum Foo {
+    Bar(int)
+}
+
+pub mod test {
+    enum Foo {
+        Bar(int)
+    }
+}

src/test/compile-fail/issue-11680.rs

@@ -0,0 +1,21 @@
+// 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.
+
+// aux-build:issue-11680.rs
+
+extern crate other = "issue-11680";
+
+fn main() {
+    let _b = other::Bar(1);
+    //~^ ERROR: variant `Bar` is private
+
+    let _b = other::test::Bar(1);
+    //~^ ERROR: variant `Bar` is private
+}