From 71e5708f15455a9cff62a291f9682642e1e291a5 Mon Sep 17 00:00:00 2001
From: Jeff Walden <jwalden@mit.edu>
Date: Mon, 9 Dec 2013 15:07:31 -0800
Subject: [PATCH] Check for an empty string before dereferencing the first
 character of the string.  No bug, rs=till

--HG--
extra : rebase_source : e4b408f772aa2460db920871086faa37c04356bb
---
 js/src/jsinferinlines.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/src/jsinferinlines.h b/js/src/jsinferinlines.h
index 429aed30eb8..5ff7c870e9c 100644
--- a/js/src/jsinferinlines.h
+++ b/js/src/jsinferinlines.h
@@ -223,7 +223,7 @@ IdToTypeId(jsid id)
     if (JSID_IS_STRING(id)) {
         JSFlatString *str = JSID_TO_FLAT_STRING(id);
         JS::TwoByteChars cp = str->range();
-        if (JS7_ISDEC(cp[0]) || cp[0] == '-') {
+        if (cp.length() > 0 && (JS7_ISDEC(cp[0]) || cp[0] == '-')) {
             for (size_t i = 1; i < cp.length(); ++i) {
                 if (!JS7_ISDEC(cp[i]))
                     return id;