From 535282bcf57f45e45cb3a01a570ab7b9ff38ee1d Mon Sep 17 00:00:00 2001
From: Nick Cameron <ncameron@mozilla.com>
Date: Wed, 6 Jan 2016 09:56:32 +1300
Subject: Cancel an error before it panics

Fixes #30715
---
 src/libsyntax/parse/parser.rs | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

(limited to 'src/libsyntax/parse')

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index db746af998d..a3318b1e8fa 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -2793,8 +2793,15 @@ impl<'a> Parser<'a> {
                     // We have 2 alternatives here: `x..y` and `x..` The other two variants are
                     // handled with `parse_prefix_range_expr` call above.
                     let rhs = if self.is_at_start_of_range_notation_rhs() {
-                        self.parse_assoc_expr_with(op.precedence() + 1,
-                                                   LhsExpr::NotYetParsed).ok()
+                        let rhs = self.parse_assoc_expr_with(op.precedence() + 1,
+                                                             LhsExpr::NotYetParsed);
+                        match rhs {
+                            Ok(e) => Some(e),
+                            Err(mut e) => {
+                                e.cancel();
+                                None
+                            }
+                        }
                     } else {
                         None
                     };
-- 
cgit 1.4.1-3-g733a5