Fix the last known (to me) bug in import resolution. We were not properly

dropping the inner part of the environment when an intermediate item resolved
in an outer scope.

3 files changed, 47 insertions, 12 deletions

diff --git a/src/Makefile b/src/Makefile
index bf757067..45d6ce80 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -448,6 +448,7 @@ TEST_XFAILS_RUSTC := $(filter-out \
                         import4.rs \
                         import5.rs \
                         import6.rs \
+                        import7.rs \
                         item-name-overload.rs \
                         large-records.rs \
                         lazy-init.rs \
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index 3ca11fed..760f86d1 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -40,11 +40,11 @@ fn lookup_name(&env e, import_map index,
                ast.ident i) -> option.t[def] {
     auto d_ = lookup_name_wrapped(e, i);
     alt (d_) {
-        case (none[def_wrap]) {
+        case (none[tup(@env, def_wrap)]) {
             ret none[def];
         }
-        case (some[def_wrap](?d)) {
-            alt (d) {
+        case (some[tup(@env, def_wrap)](?d)) {
+            alt (d._1) {
                 case (def_wrap_use(?it)) {
                     alt (it.node) {
                         case (ast.view_item_use(_, _, ?id)) {
@@ -115,14 +115,14 @@ fn find_final_def(&env e, &span sp, vec[ident] idents) -> def_wrap {
                 auto next_i = rest_idents.(0);
                 auto next_ = lookup_name_wrapped(tmp_e, next_i);
                 alt (next_) {
-                    case (none[def_wrap]) {
+                    case (none[tup(@env, def_wrap)]) {
                         e.sess.span_err(sp, "unresolved name: " + next_i);
                         fail;
                     }
-                    case (some[def_wrap](?next)) {
+                    case (some[tup(@env, def_wrap)](?next)) {
                         auto combined_e = update_env_for_item(e, i);
                         ret found_something(combined_e, pending, sp,
-                                            rest_idents, next);
+                                            rest_idents, next._1);
                     }
                 }
             }
@@ -141,12 +141,12 @@ fn find_final_def(&env e, &span sp, vec[ident] idents) -> def_wrap {
         auto first = idents.(0);
         auto d_ = lookup_name_wrapped(e, first);
         alt (d_) {
-            case (none[def_wrap]) {
+            case (none[tup(@env, def_wrap)]) {
                 e.sess.span_err(sp, "unresolved name: " + first);
                 fail;
             }
-            case (some[def_wrap](?d)) {
-                ret found_something(e, pending, sp, idents, d);
+            case (some[tup(@env, def_wrap)](?d)) {
+                ret found_something(*d._0, pending, sp, idents, d._1);
             }
         }
     }
@@ -154,7 +154,7 @@ fn find_final_def(&env e, &span sp, vec[ident] idents) -> def_wrap {
     ret inner(e, pending, sp, idents);
 }
 
-fn lookup_name_wrapped(&env e, ast.ident i) -> option.t[def_wrap] {
+fn lookup_name_wrapped(&env e, ast.ident i) -> option.t[tup(@env, def_wrap)] {
 
     // log "resolving name " + i;
 
@@ -308,8 +308,23 @@ fn lookup_name_wrapped(&env e, ast.ident i) -> option.t[def_wrap] {
         ret none[def_wrap];
     }
 
-    ret std.list.find[scope,def_wrap](e.scopes,
-                                      bind in_scope(i, _));
+    alt (e.scopes) {
+        case (nil[scope]) {
+            ret none[tup(@env, def_wrap)];
+        }
+        case (cons[scope](?hd, ?tl)) {
+            auto x = in_scope(i, hd);
+            alt (x) {
+                case (some[def_wrap](?x)) {
+                    ret some(tup(@e, x));
+                }
+                case (none[def_wrap]) {
+                    auto outer_env = rec(scopes = *tl with e);
+                    ret lookup_name_wrapped(outer_env, i);
+                }
+            }
+        }
+    }
 }
 
 fn fold_pat_tag(&env e, &span sp, import_map index, ident i,
diff --git a/src/test/run-pass/import7.rs b/src/test/run-pass/import7.rs
new file mode 100644
index 00000000..29915fb1
--- /dev/null
+++ b/src/test/run-pass/import7.rs
@@ -0,0 +1,19 @@
+import bar.baz;
+import foo.zed;
+mod foo {
+  mod zed {
+    fn baz() {
+      log "baz";
+    }
+  }
+}
+mod bar {
+  import zed.baz;
+  mod foo {
+    mod zed {
+    }
+  }
+}
+fn main(vec[str] args) {
+  baz();
+}