From 74c714bce9ed2e6b5bdd86397cf1909153ef2c61 Mon Sep 17 00:00:00 2001
From: Chris Cowan <agentme49@gmail.com>
Date: Thu, 14 May 2015 12:03:54 -0700
Subject: [PATCH] Give a good error message if an invalid regular expression is
 found.

---
 lib/parse.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/parse.js b/lib/parse.js
index 3cc2da51..b6645f49 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -480,7 +480,13 @@ function tokenizer($TEXT, filename, html5_comments) {
             regexp += ch;
         }
         var mods = read_name();
-        return token("regexp", new RegExp(regexp, mods));
+        var r;
+        try {
+          r = new RegExp(regexp, mods);
+        } catch(e) {
+          parse_error("Invalid regular expression");
+        }
+        return token("regexp", r);
     });
 
     function read_operator(prefix) {