5 files changed, 197 insertions, 97 deletions

diff --git a/libgo/go/strconv/atoi.go b/libgo/go/strconv/atoi.go
index cbf0380ec82..9ecec5a58b9 100644
--- a/libgo/go/strconv/atoi.go
+++ b/libgo/go/strconv/atoi.go
@@ -31,7 +31,7 @@ func rangeError(fn, str string) *NumError {
 	return &NumError{fn, str, ErrRange}
 }
 
-const intSize = 32 << uint(^uint(0)>>63)
+const intSize = 32 << (^uint(0) >> 63)
 
 // IntSize is the size in bits of an int or uint value.
 const IntSize = intSize
diff --git a/libgo/go/strconv/isprint.go b/libgo/go/strconv/isprint.go
index 91f1795356b..80738ed7111 100644
--- a/libgo/go/strconv/isprint.go
+++ b/libgo/go/strconv/isprint.go
@@ -3,20 +3,19 @@
 // license that can be found in the LICENSE file.
 
 // DO NOT EDIT.  GENERATED BY
-//     go run makeisprint.go >x && mv x isprint.go
+//     go run makeisprint.go -output isprint.go
 
 package strconv
 
-// (470+136+60)*2 + (218)*4 = 2204 bytes
+// (468+138+67)*2 + (326)*4 = 2650 bytes
 
 var isPrint16 = []uint16{
 	0x0020, 0x007e,
 	0x00a1, 0x0377,
-	0x037a, 0x037e,
-	0x0384, 0x0527,
-	0x0531, 0x0556,
+	0x037a, 0x037f,
+	0x0384, 0x0556,
 	0x0559, 0x058a,
-	0x058f, 0x05c7,
+	0x058d, 0x05c7,
 	0x05d0, 0x05ea,
 	0x05f0, 0x05f4,
 	0x0606, 0x061b,
@@ -27,7 +26,7 @@ var isPrint16 = []uint16{
 	0x0800, 0x082d,
 	0x0830, 0x085b,
 	0x085e, 0x085e,
-	0x08a0, 0x08ac,
+	0x08a0, 0x08b2,
 	0x08e4, 0x098c,
 	0x098f, 0x0990,
 	0x0993, 0x09b2,
@@ -72,18 +71,17 @@ var isPrint16 = []uint16{
 	0x0bd0, 0x0bd0,
 	0x0bd7, 0x0bd7,
 	0x0be6, 0x0bfa,
-	0x0c01, 0x0c39,
+	0x0c00, 0x0c39,
 	0x0c3d, 0x0c4d,
 	0x0c55, 0x0c59,
 	0x0c60, 0x0c63,
 	0x0c66, 0x0c6f,
-	0x0c78, 0x0c7f,
-	0x0c82, 0x0cb9,
+	0x0c78, 0x0cb9,
 	0x0cbc, 0x0ccd,
 	0x0cd5, 0x0cd6,
 	0x0cde, 0x0ce3,
 	0x0ce6, 0x0cf2,
-	0x0d02, 0x0d3a,
+	0x0d01, 0x0d3a,
 	0x0d3d, 0x0d4e,
 	0x0d57, 0x0d57,
 	0x0d60, 0x0d63,
@@ -94,6 +92,7 @@ var isPrint16 = []uint16{
 	0x0dc0, 0x0dc6,
 	0x0dca, 0x0dca,
 	0x0dcf, 0x0ddf,
+	0x0de6, 0x0def,
 	0x0df2, 0x0df4,
 	0x0e01, 0x0e3a,
 	0x0e3f, 0x0e5b,
@@ -120,7 +119,7 @@ var isPrint16 = []uint16{
 	0x1380, 0x1399,
 	0x13a0, 0x13f4,
 	0x1400, 0x169c,
-	0x16a0, 0x16f0,
+	0x16a0, 0x16f8,
 	0x1700, 0x1714,
 	0x1720, 0x1736,
 	0x1740, 0x1753,
@@ -133,8 +132,7 @@ var isPrint16 = []uint16{
 	0x1820, 0x1877,
 	0x1880, 0x18aa,
 	0x18b0, 0x18f5,
-	0x1900, 0x191c,
-	0x1920, 0x192b,
+	0x1900, 0x192b,
 	0x1930, 0x193b,
 	0x1940, 0x1940,
 	0x1944, 0x196d,
@@ -147,6 +145,7 @@ var isPrint16 = []uint16{
 	0x1a7f, 0x1a89,
 	0x1a90, 0x1a99,
 	0x1aa0, 0x1aad,
+	0x1ab0, 0x1abe,
 	0x1b00, 0x1b4b,
 	0x1b50, 0x1b7c,
 	0x1b80, 0x1bf3,
@@ -154,8 +153,8 @@ var isPrint16 = []uint16{
 	0x1c3b, 0x1c49,
 	0x1c4d, 0x1c7f,
 	0x1cc0, 0x1cc7,
-	0x1cd0, 0x1cf6,
-	0x1d00, 0x1de6,
+	0x1cd0, 0x1cf9,
+	0x1d00, 0x1df5,
 	0x1dfc, 0x1f15,
 	0x1f18, 0x1f1d,
 	0x1f20, 0x1f45,
@@ -168,21 +167,23 @@ var isPrint16 = []uint16{
 	0x2030, 0x205e,
 	0x2070, 0x2071,
 	0x2074, 0x209c,
-	0x20a0, 0x20ba,
+	0x20a0, 0x20bd,
 	0x20d0, 0x20f0,
 	0x2100, 0x2189,
-	0x2190, 0x23f3,
+	0x2190, 0x23fa,
 	0x2400, 0x2426,
 	0x2440, 0x244a,
-	0x2460, 0x2b4c,
-	0x2b50, 0x2b59,
+	0x2460, 0x2b73,
+	0x2b76, 0x2b95,
+	0x2b98, 0x2bb9,
+	0x2bbd, 0x2bd1,
 	0x2c00, 0x2cf3,
 	0x2cf9, 0x2d27,
 	0x2d2d, 0x2d2d,
 	0x2d30, 0x2d67,
 	0x2d6f, 0x2d70,
 	0x2d7f, 0x2d96,
-	0x2da0, 0x2e3b,
+	0x2da0, 0x2e42,
 	0x2e80, 0x2ef3,
 	0x2f00, 0x2fd5,
 	0x2ff0, 0x2ffb,
@@ -196,11 +197,10 @@ var isPrint16 = []uint16{
 	0xa000, 0xa48c,
 	0xa490, 0xa4c6,
 	0xa4d0, 0xa62b,
-	0xa640, 0xa697,
-	0xa69f, 0xa6f7,
-	0xa700, 0xa793,
-	0xa7a0, 0xa7aa,
-	0xa7f8, 0xa82b,
+	0xa640, 0xa6f7,
+	0xa700, 0xa7ad,
+	0xa7b0, 0xa7b1,
+	0xa7f7, 0xa82b,
 	0xa830, 0xa839,
 	0xa840, 0xa877,
 	0xa880, 0xa8c4,
@@ -209,17 +209,16 @@ var isPrint16 = []uint16{
 	0xa900, 0xa953,
 	0xa95f, 0xa97c,
 	0xa980, 0xa9d9,
-	0xa9de, 0xa9df,
-	0xaa00, 0xaa36,
+	0xa9de, 0xaa36,
 	0xaa40, 0xaa4d,
 	0xaa50, 0xaa59,
-	0xaa5c, 0xaa7b,
-	0xaa80, 0xaac2,
+	0xaa5c, 0xaac2,
 	0xaadb, 0xaaf6,
 	0xab01, 0xab06,
 	0xab09, 0xab0e,
 	0xab11, 0xab16,
-	0xab20, 0xab2e,
+	0xab20, 0xab5f,
+	0xab64, 0xab65,
 	0xabc0, 0xabed,
 	0xabf0, 0xabf9,
 	0xac00, 0xd7a3,
@@ -235,7 +234,7 @@ var isPrint16 = []uint16{
 	0xfd92, 0xfdc7,
 	0xfdf0, 0xfdfd,
 	0xfe00, 0xfe19,
-	0xfe20, 0xfe26,
+	0xfe20, 0xfe2d,
 	0xfe30, 0xfe6b,
 	0xfe70, 0xfefc,
 	0xff01, 0xffbe,
@@ -252,15 +251,12 @@ var isNotPrint16 = []uint16{
 	0x038b,
 	0x038d,
 	0x03a2,
+	0x0530,
 	0x0560,
 	0x0588,
 	0x0590,
 	0x06dd,
 	0x083f,
-	0x08a1,
-	0x08ff,
-	0x0978,
-	0x0980,
 	0x0984,
 	0x09a9,
 	0x09b1,
@@ -294,10 +290,10 @@ var isNotPrint16 = []uint16{
 	0x0c0d,
 	0x0c11,
 	0x0c29,
-	0x0c34,
 	0x0c45,
 	0x0c49,
 	0x0c57,
+	0x0c80,
 	0x0c84,
 	0x0c8d,
 	0x0c91,
@@ -345,7 +341,9 @@ var isNotPrint16 = []uint16{
 	0x170d,
 	0x176d,
 	0x1771,
+	0x191f,
 	0x1a5f,
+	0x1cf7,
 	0x1f58,
 	0x1f5a,
 	0x1f5c,
@@ -355,7 +353,7 @@ var isNotPrint16 = []uint16{
 	0x1fdc,
 	0x1ff5,
 	0x208f,
-	0x2700,
+	0x2bc9,
 	0x2c2f,
 	0x2c5f,
 	0x2d26,
@@ -372,9 +370,12 @@ var isNotPrint16 = []uint16{
 	0x318f,
 	0x321f,
 	0x32ff,
+	0xa69e,
 	0xa78f,
 	0xa9ce,
+	0xa9ff,
 	0xab27,
+	0xab2f,
 	0xfb37,
 	0xfb3d,
 	0xfb3f,
@@ -392,21 +393,31 @@ var isPrint32 = []uint32{
 	0x010080, 0x0100fa,
 	0x010100, 0x010102,
 	0x010107, 0x010133,
-	0x010137, 0x01018a,
+	0x010137, 0x01018c,
 	0x010190, 0x01019b,
+	0x0101a0, 0x0101a0,
 	0x0101d0, 0x0101fd,
 	0x010280, 0x01029c,
 	0x0102a0, 0x0102d0,
+	0x0102e0, 0x0102fb,
 	0x010300, 0x010323,
 	0x010330, 0x01034a,
+	0x010350, 0x01037a,
 	0x010380, 0x0103c3,
 	0x0103c8, 0x0103d5,
 	0x010400, 0x01049d,
 	0x0104a0, 0x0104a9,
+	0x010500, 0x010527,
+	0x010530, 0x010563,
+	0x01056f, 0x01056f,
+	0x010600, 0x010736,
+	0x010740, 0x010755,
+	0x010760, 0x010767,
 	0x010800, 0x010805,
 	0x010808, 0x010838,
 	0x01083c, 0x01083c,
-	0x01083f, 0x01085f,
+	0x01083f, 0x01089e,
+	0x0108a7, 0x0108af,
 	0x010900, 0x01091b,
 	0x01091f, 0x010939,
 	0x01093f, 0x01093f,
@@ -417,32 +428,72 @@ var isPrint32 = []uint32{
 	0x010a38, 0x010a3a,
 	0x010a3f, 0x010a47,
 	0x010a50, 0x010a58,
-	0x010a60, 0x010a7f,
+	0x010a60, 0x010a9f,
+	0x010ac0, 0x010ae6,
+	0x010aeb, 0x010af6,
 	0x010b00, 0x010b35,
 	0x010b39, 0x010b55,
 	0x010b58, 0x010b72,
-	0x010b78, 0x010b7f,
+	0x010b78, 0x010b91,
+	0x010b99, 0x010b9c,
+	0x010ba9, 0x010baf,
 	0x010c00, 0x010c48,
 	0x010e60, 0x010e7e,
 	0x011000, 0x01104d,
 	0x011052, 0x01106f,
-	0x011080, 0x0110c1,
+	0x01107f, 0x0110c1,
 	0x0110d0, 0x0110e8,
 	0x0110f0, 0x0110f9,
 	0x011100, 0x011143,
+	0x011150, 0x011176,
 	0x011180, 0x0111c8,
-	0x0111d0, 0x0111d9,
+	0x0111cd, 0x0111cd,
+	0x0111d0, 0x0111da,
+	0x0111e1, 0x0111f4,
+	0x011200, 0x01123d,
+	0x0112b0, 0x0112ea,
+	0x0112f0, 0x0112f9,
+	0x011301, 0x01130c,
+	0x01130f, 0x011310,
+	0x011313, 0x011339,
+	0x01133c, 0x011344,
+	0x011347, 0x011348,
+	0x01134b, 0x01134d,
+	0x011357, 0x011357,
+	0x01135d, 0x011363,
+	0x011366, 0x01136c,
+	0x011370, 0x011374,
+	0x011480, 0x0114c7,
+	0x0114d0, 0x0114d9,
+	0x011580, 0x0115b5,
+	0x0115b8, 0x0115c9,
+	0x011600, 0x011644,
+	0x011650, 0x011659,
 	0x011680, 0x0116b7,
 	0x0116c0, 0x0116c9,
-	0x012000, 0x01236e,
-	0x012400, 0x012462,
-	0x012470, 0x012473,
+	0x0118a0, 0x0118f2,
+	0x0118ff, 0x0118ff,
+	0x011ac0, 0x011af8,
+	0x012000, 0x012398,
+	0x012400, 0x012474,
 	0x013000, 0x01342e,
 	0x016800, 0x016a38,
+	0x016a40, 0x016a69,
+	0x016a6e, 0x016a6f,
+	0x016ad0, 0x016aed,
+	0x016af0, 0x016af5,
+	0x016b00, 0x016b45,
+	0x016b50, 0x016b77,
+	0x016b7d, 0x016b8f,
 	0x016f00, 0x016f44,
 	0x016f50, 0x016f7e,
 	0x016f8f, 0x016f9f,
 	0x01b000, 0x01b001,
+	0x01bc00, 0x01bc6a,
+	0x01bc70, 0x01bc7c,
+	0x01bc80, 0x01bc88,
+	0x01bc90, 0x01bc99,
+	0x01bc9c, 0x01bc9f,
 	0x01d000, 0x01d0f5,
 	0x01d100, 0x01d126,
 	0x01d129, 0x01d172,
@@ -458,6 +509,8 @@ var isPrint32 = []uint32{
 	0x01d54a, 0x01d6a5,
 	0x01d6a8, 0x01d7cb,
 	0x01d7ce, 0x01d7ff,
+	0x01e800, 0x01e8c4,
+	0x01e8c7, 0x01e8d6,
 	0x01ee00, 0x01ee24,
 	0x01ee27, 0x01ee3b,
 	0x01ee42, 0x01ee42,
@@ -469,28 +522,30 @@ var isPrint32 = []uint32{
 	0x01f000, 0x01f02b,
 	0x01f030, 0x01f093,
 	0x01f0a0, 0x01f0ae,
-	0x01f0b1, 0x01f0be,
-	0x01f0c1, 0x01f0df,
-	0x01f100, 0x01f10a,
+	0x01f0b1, 0x01f0f5,
+	0x01f100, 0x01f10c,
 	0x01f110, 0x01f16b,
 	0x01f170, 0x01f19a,
 	0x01f1e6, 0x01f202,
 	0x01f210, 0x01f23a,
 	0x01f240, 0x01f248,
 	0x01f250, 0x01f251,
-	0x01f300, 0x01f320,
-	0x01f330, 0x01f37c,
-	0x01f380, 0x01f393,
-	0x01f3a0, 0x01f3ca,
-	0x01f3e0, 0x01f3f0,
-	0x01f400, 0x01f4fc,
-	0x01f500, 0x01f53d,
-	0x01f540, 0x01f543,
-	0x01f550, 0x01f567,
-	0x01f5fb, 0x01f640,
-	0x01f645, 0x01f64f,
-	0x01f680, 0x01f6c5,
+	0x01f300, 0x01f32c,
+	0x01f330, 0x01f37d,
+	0x01f380, 0x01f3ce,
+	0x01f3d4, 0x01f3f7,
+	0x01f400, 0x01f54a,
+	0x01f550, 0x01f642,
+	0x01f645, 0x01f6cf,
+	0x01f6e0, 0x01f6ec,
+	0x01f6f0, 0x01f6f3,
 	0x01f700, 0x01f773,
+	0x01f780, 0x01f7d4,
+	0x01f800, 0x01f80b,
+	0x01f810, 0x01f847,
+	0x01f850, 0x01f859,
+	0x01f860, 0x01f887,
+	0x01f890, 0x01f8ad,
 	0x020000, 0x02a6d6,
 	0x02a700, 0x02b734,
 	0x02b740, 0x02b81d,
@@ -503,7 +558,6 @@ var isNotPrint32 = []uint16{ // add 0x10000 to each entry
 	0x0027,
 	0x003b,
 	0x003e,
-	0x031f,
 	0x039e,
 	0x0809,
 	0x0836,
@@ -513,6 +567,15 @@ var isNotPrint32 = []uint16{ // add 0x10000 to each entry
 	0x0a18,
 	0x10bd,
 	0x1135,
+	0x1212,
+	0x1304,
+	0x1329,
+	0x1331,
+	0x1334,
+	0x246f,
+	0x6a5f,
+	0x6b5a,
+	0x6b62,
 	0xd455,
 	0xd49d,
 	0xd4ad,
@@ -552,11 +615,10 @@ var isNotPrint32 = []uint16{ // add 0x10000 to each entry
 	0xee8a,
 	0xeea4,
 	0xeeaa,
+	0xf0c0,
 	0xf0d0,
 	0xf12f,
-	0xf336,
-	0xf3c5,
-	0xf43f,
-	0xf441,
-	0xf4f8,
+	0xf4ff,
+	0xf57a,
+	0xf5a4,
 }
diff --git a/libgo/go/strconv/makeisprint.go b/libgo/go/strconv/makeisprint.go
index 216159cc020..588d0a00b53 100644
--- a/libgo/go/strconv/makeisprint.go
+++ b/libgo/go/strconv/makeisprint.go
@@ -4,15 +4,26 @@
 
 // +build ignore
 
-// makeisprint generates the tables for strconv's compact isPrint.
+//
+// usage:
+//
+// go run makeisprint.go -output isprint.go
+//
+
 package main
 
 import (
+	"bytes"
+	"flag"
 	"fmt"
-	"os"
+	"go/format"
+	"io/ioutil"
+	"log"
 	"unicode"
 )
 
+var filename = flag.String("output", "isprint.go", "output file name")
+
 var (
 	range16  []uint16
 	except16 []uint16
@@ -110,6 +121,8 @@ func to16(x []uint32) []uint16 {
 }
 
 func main() {
+	flag.Parse()
+
 	rang, except := scan(0, 0xFFFF)
 	range16 = to16(rang)
 	except16 = to16(except)
@@ -117,49 +130,58 @@ func main() {
 
 	for i := rune(0); i <= unicode.MaxRune; i++ {
 		if isPrint(i) != unicode.IsPrint(i) {
-			fmt.Fprintf(os.Stderr, "%U: isPrint=%v, want %v\n", i, isPrint(i), unicode.IsPrint(i))
-			return
+			log.Fatalf("%U: isPrint=%v, want %v\n", i, isPrint(i), unicode.IsPrint(i))
 		}
 	}
 
-	fmt.Printf(`// Copyright 2013 The Go Authors. All rights reserved.
+	var buf bytes.Buffer
+
+	fmt.Fprintf(&buf, `// Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.` + "\n\n")
-	fmt.Printf("// DO NOT EDIT.  GENERATED BY\n")
-	fmt.Printf("//     go run makeisprint.go >x && mv x isprint.go\n\n")
-	fmt.Printf("package strconv\n\n")
+// license that can be found in the LICENSE file.`+"\n\n")
+	fmt.Fprintf(&buf, "// DO NOT EDIT.  GENERATED BY\n")
+	fmt.Fprintf(&buf, "//     go run makeisprint.go -output isprint.go\n\n")
+	fmt.Fprintf(&buf, "package strconv\n\n")
 
-	fmt.Printf("// (%d+%d+%d)*2 + (%d)*4 = %d bytes\n\n",
+	fmt.Fprintf(&buf, "// (%d+%d+%d)*2 + (%d)*4 = %d bytes\n\n",
 		len(range16), len(except16), len(except32),
 		len(range32),
 		(len(range16)+len(except16)+len(except32))*2+
 			(len(range32))*4)
 
-	fmt.Printf("var isPrint16 = []uint16{\n")
+	fmt.Fprintf(&buf, "var isPrint16 = []uint16{\n")
 	for i := 0; i < len(range16); i += 2 {
-		fmt.Printf("\t%#04x, %#04x,\n", range16[i], range16[i+1])
+		fmt.Fprintf(&buf, "\t%#04x, %#04x,\n", range16[i], range16[i+1])
 	}
-	fmt.Printf("}\n\n")
+	fmt.Fprintf(&buf, "}\n\n")
 
-	fmt.Printf("var isNotPrint16 = []uint16{\n")
+	fmt.Fprintf(&buf, "var isNotPrint16 = []uint16{\n")
 	for _, r := range except16 {
-		fmt.Printf("\t%#04x,\n", r)
+		fmt.Fprintf(&buf, "\t%#04x,\n", r)
 	}
-	fmt.Printf("}\n\n")
+	fmt.Fprintf(&buf, "}\n\n")
 
-	fmt.Printf("var isPrint32 = []uint32{\n")
+	fmt.Fprintf(&buf, "var isPrint32 = []uint32{\n")
 	for i := 0; i < len(range32); i += 2 {
-		fmt.Printf("\t%#06x, %#06x,\n", range32[i], range32[i+1])
+		fmt.Fprintf(&buf, "\t%#06x, %#06x,\n", range32[i], range32[i+1])
 	}
-	fmt.Printf("}\n\n")
+	fmt.Fprintf(&buf, "}\n\n")
 
-	fmt.Printf("var isNotPrint32 = []uint16{ // add 0x10000 to each entry\n")
+	fmt.Fprintf(&buf, "var isNotPrint32 = []uint16{ // add 0x10000 to each entry\n")
 	for _, r := range except32 {
 		if r >= 0x20000 {
-			fmt.Fprintf(os.Stderr, "%U too big for isNotPrint32\n", r)
-			return
+			log.Fatalf("%U too big for isNotPrint32\n", r)
 		}
-		fmt.Printf("\t%#04x,\n", r-0x10000)
+		fmt.Fprintf(&buf, "\t%#04x,\n", r-0x10000)
+	}
+	fmt.Fprintf(&buf, "}\n")
+
+	data, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = ioutil.WriteFile(*filename, data, 0644)
+	if err != nil {
+		log.Fatal(err)
 	}
-	fmt.Printf("}\n")
 }
diff --git a/libgo/go/strconv/quote.go b/libgo/go/strconv/quote.go
index aded7e5930c..53d51b5a46a 100644
--- a/libgo/go/strconv/quote.go
+++ b/libgo/go/strconv/quote.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:generate go run makeisprint.go -output isprint.go
+
 package strconv
 
 import (
@@ -141,11 +143,21 @@ func AppendQuoteRuneToASCII(dst []byte, r rune) []byte {
 
 // CanBackquote reports whether the string s can be represented
 // unchanged as a single-line backquoted string without control
-// characters other than space and tab.
+// characters other than tab.
 func CanBackquote(s string) bool {
-	for i := 0; i < len(s); i++ {
-		c := s[i]
-		if (c < ' ' && c != '\t') || c == '`' || c == '\u007F' {
+	for len(s) > 0 {
+		r, wid := utf8.DecodeRuneInString(s)
+		s = s[wid:]
+		if wid > 1 {
+			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
+		}
+		if (r < ' ' && r != '\t') || r == '`' || r == '\u007F' {
 			return false
 		}
 	}
diff --git a/libgo/go/strconv/quote_test.go b/libgo/go/strconv/quote_test.go
index e4b5b6b9fd2..3bf162f987e 100644
--- a/libgo/go/strconv/quote_test.go
+++ b/libgo/go/strconv/quote_test.go
@@ -146,6 +146,10 @@ var canbackquotetests = []canBackquoteTest{
 	{`ABCDEFGHIJKLMNOPQRSTUVWXYZ`, true},
 	{`abcdefghijklmnopqrstuvwxyz`, true},
 	{`☺`, true},
+	{"\x80", false},
+	{"a\xe0\xa0z", false},
+	{"\ufeffabc", false},
+	{"a\ufeffz", false},
 }
 
 func TestCanBackquote(t *testing.T) {