---

yaml
---
r: 153113
b: refs/heads/try2
c: 6bee3c8
h: refs/heads/master
i:
  153111: 5afaa5f
v: v3

Author: jbclements

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 35175f015ff878d49e3b5562fe3a7addcef25cfc
+refs/heads/try2: 6bee3c87c94a39fb7d48a119bbc105149c345bfc
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/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));