---

yaml
---
r: 277039
b: refs/heads/try
c: 3238b4b
h: refs/heads/master
i:
  277037: bdac99a
  277035: 405e1b2
  277031: f3d069e
  277023: e606f00

Author: jseyfried

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 6dbb0e86aec11050480beb76eade6fb805010ba7
 refs/heads/snap-stage3: 235d77457d80b549dad3ac36d94f235208a1eafb
-refs/heads/try: faea5ff6efae623c052e59120d18306cc6d9fd4a
+refs/heads/try: 3238b4bbbdd5b0a8c64ebeaedfa989d1babb3c21
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try/src/librustc_resolve/resolve_imports.rs

@@ -317,6 +317,8 @@ impl<'a> ::ModuleS<'a> {
     fn update_resolution<T, F>(&self, name: Name, ns: Namespace, update: F) -> T
         where F: FnOnce(&mut NameResolution<'a>) -> T
     {
+        // Ensure that `resolution` isn't borrowed during `define_in_glob_importers`,
+        // where it might end up getting re-defined via a glob cycle.
         let (new_binding, t) = {
             let mut resolution = &mut *self.resolution(name, ns).borrow_mut();
             let was_known = resolution.binding().is_some();
@@ -650,6 +652,8 @@ impl<'a, 'b:'a, 'tcx:'b> ImportResolver<'a, 'b, 'tcx> {
         // Add to target_module's glob_importers
         target_module.glob_importers.borrow_mut().push((module_, directive));
 
+        // Ensure that `resolutions` isn't borrowed during `try_define_child`,
+        // since it might get updated via a glob cycle.
         let bindings = target_module.resolutions.borrow().iter().filter_map(|(name, resolution)| {
             resolution.borrow().binding().map(|binding| (*name, binding))
         }).collect::<Vec<_>>();