---

yaml
---
r: 122835
b: refs/heads/master
c: 6bee3c8
h: refs/heads/master
i:
  122833: c16b907
  122831: c2173c3
v: v3

Author: jbclements

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 35175f015ff878d49e3b5562fe3a7addcef25cfc
+refs/heads/master: 6bee3c87c94a39fb7d48a119bbc105149c345bfc
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: aaff4e05e19b48d81e4ecb3337f288f42d06edd0
 refs/heads/try: 2e9d9477b848cec778ca3f07ecdf0aea6ade23de

trunk/src/libsyntax/ext/expand.rs

@@ -667,19 +667,14 @@ fn expand_arm(arm: &ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
     // code duplicated from 'let', above. Perhaps this can be lifted
     // into a separate function:
     let idents = pattern_bindings(*first_pat);
-    let mut new_pending_renames =
+    let new_pending_renames =
         idents.iter().map(|id| (*id,fresh_name(id))).collect();
-    // rewrite all of the patterns using the new names (the old
-    // ones have already been applied). Note that we depend here
-    // on the guarantee that after expansion, there can't be any
-    // Path expressions (a.k.a. varrefs) left in the pattern. If
-    // this were false, we'd need to apply this renaming only to
-    // the bindings, and not to the varrefs, using a more targeted
-    // fold-er.
-    let mut rename_fld = IdentRenamer{renames:&mut new_pending_renames};
+    // apply the renaming, but only to the PatIdents:
+    let mut rename_pats_fld = PatIdentRenamer{renames:&new_pending_renames};
     let rewritten_pats =
-        expanded_pats.iter().map(|pat| rename_fld.fold_pat(*pat)).collect();
+        expanded_pats.iter().map(|pat| rename_pats_fld.fold_pat(*pat)).collect();
     // apply renaming and then expansion to the guard and the body:
+    let mut rename_fld = IdentRenamer{renames:&new_pending_renames};
     let rewritten_guard =
         arm.guard.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
     let rewritten_body = fld.fold_expr(rename_fld.fold_expr(arm.body));