---

yaml
---
r: 278263
b: refs/heads/beta
c: 8bede43
h: refs/heads/master
i:
  278261: f0b0578
  278259: 0563577
  278255: 8bc02cc

Author: jseyfried

[refs]

@@ -23,7 +23,7 @@ refs/tags/0.9: 36870b185fc5f5486636d4515f0e22677493f225
 refs/tags/0.10: ac33f2b15782272ae348dbd7b14b8257b2148b5a
 refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
-refs/heads/beta: 6f61c942b63c5861e574ca92fe1d9beeec60c4ab
+refs/heads/beta: 8bede4302a086afd78af89e9b64d5d0757f637e3
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: e06d2ad9fcd5027bcaac5b08fc9aa39a49d0ecd3
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f

branches/beta/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<_>>();