From: Volker Dobler <dr.volker.dobler@gmail.com>
Date: Wed, 16 Jul 2014 20:06:11 +0000 (-0700)
Subject: strconv: fix handling of BOMs in CanBackquote
X-Git-Tag: go1.4beta1~1085
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=3b1b84069956bc8f21be37c563d0ba8da93a87d1;p=gostls13.git

strconv: fix handling of BOMs in CanBackquote

A byte order mark  (BOM) cannot be backquoted.

LGTM=r
R=golang-codereviews, gobot, r
CC=golang-codereviews
https://golang.org/cl/112310043
---

diff --git a/src/pkg/strconv/quote.go b/src/pkg/strconv/quote.go
index 89dda99750..8cdfc472f3 100644
--- a/src/pkg/strconv/quote.go
+++ b/src/pkg/strconv/quote.go
@@ -147,7 +147,10 @@ func CanBackquote(s string) bool {
 		r, wid := utf8.DecodeRuneInString(s)
 		s = s[wid:]
 		if wid > 1 {
-			continue // All multibyte runes are correctly encoded and assumed printable.
+			if r == '\ufeff' {
+				return false // BOMs are invisible and should not be quoted.
+			}
+			continue // All other multibyte runes are correctly encoded and assumed printable.
 		}
 		if r == utf8.RuneError {
 			return false
diff --git a/src/pkg/strconv/quote_test.go b/src/pkg/strconv/quote_test.go
index 24998191d7..3bf162f987 100644
--- a/src/pkg/strconv/quote_test.go
+++ b/src/pkg/strconv/quote_test.go
@@ -148,8 +148,8 @@ var canbackquotetests = []canBackquoteTest{
 	{`☺`, true},
 	{"\x80", false},
 	{"a\xe0\xa0z", false},
-	{"\ufeffabc", true},
-	{"a\ufeffz", true},
+	{"\ufeffabc", false},
+	{"a\ufeffz", false},
 }
 
 func TestCanBackquote(t *testing.T) {