Workaround for imports with empty braces

Author: petrochenkov

src/librustc_front/visit.rs

@@ -218,8 +218,8 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                             visitor.visit_path_list_item(prefix, item)
                         }
                     } else {
-                        // FIXME: uncomment this and fix the resulting ICE
-                        // visitor.visit_path(prefix, item.id);
+                        // FIXME(#28388) visit_path should be used instead of walk_path
+                        walk_path(visitor, prefix);
                     }
                 }
             }

src/librustc_privacy/lib.rs

@@ -980,15 +980,19 @@ impl<'a, 'tcx, 'v> Visitor<'v> for PrivacyVisitor<'a, 'tcx> {
     }
 
     fn visit_path(&mut self, path: &hir::Path, id: ast::NodeId) {
-        self.check_path(path.span, id, path.segments.last().unwrap().identifier.name);
-        visit::walk_path(self, path);
+        if !path.segments.is_empty() {
+            self.check_path(path.span, id, path.segments.last().unwrap().identifier.name);
+            visit::walk_path(self, path);
+        }
     }
 
     fn visit_path_list_item(&mut self, prefix: &hir::Path, item: &hir::PathListItem) {
         let name = if let hir::PathListIdent { name, .. } = item.node {
             name.name
-        } else {
+        } else if !prefix.segments.is_empty() {
             prefix.segments.last().unwrap().identifier.name
+        } else {
+            self.tcx.sess.bug("`self` import in an import list with empty prefix");
         };
         self.check_path(item.span, item.node.id(), name);
         visit::walk_path_list_item(self, prefix, item);

src/libstd/lib.rs

@@ -201,7 +201,6 @@
 
 #![feature(alloc)]
 #![feature(allow_internal_unstable)]
-#![feature(arc_weak)]
 #![feature(associated_consts)]
 #![feature(borrow_state)]
 #![feature(box_syntax)]

src/libsyntax/visit.rs

@@ -224,8 +224,8 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                             visitor.visit_path_list_item(prefix, item)
                         }
                     } else {
-                        // FIXME: uncomment this and fix the resulting ICE
-                        // visitor.visit_path(prefix, item.id);
+                        // FIXME(#28388) visit_path should be used instead of walk_path
+                        walk_path(visitor, prefix);
                     }
                 }
             }

src/test/compile-fail/issue-28075.rs

@@ -12,11 +12,10 @@
 
 #![allow(unused_imports)]
 
-use std::thread::{catch_panic, sleep}; //~ ERROR use of unstable library feature 'catch_panic'
-//~^ ERROR use of unstable library feature 'thread_sleep'
+use std::thread::{catch_panic, ScopedKey}; //~ ERROR use of unstable library feature 'catch_panic'
+//~^ ERROR use of unstable library feature 'scoped_tls'
 
 use std::rt::{self}; //~ ERROR use of unstable library feature 'rt'
-use std::rt::{};
 
 fn main() {
 }