4 files changed, 77 insertions, 55 deletions
diff --git a/vendor/github.com/mattn/go-runewidth/go.mod b/vendor/github.com/mattn/go-runewidth/go.mod
index fa7f4d86..62dba1bf 100644
--- a/vendor/github.com/mattn/go-runewidth/go.mod
+++ b/vendor/github.com/mattn/go-runewidth/go.mod
@@ -1,3 +1,5 @@
 module github.com/mattn/go-runewidth
 
 go 1.9
+
+require github.com/rivo/uniseg v0.2.0
diff --git a/vendor/github.com/mattn/go-runewidth/go.sum b/vendor/github.com/mattn/go-runewidth/go.sum
new file mode 100644
index 00000000..03f902d5
--- /dev/null
+++ b/vendor/github.com/mattn/go-runewidth/go.sum
@@ -0,0 +1,2 @@
+github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
diff --git a/vendor/github.com/mattn/go-runewidth/runewidth.go b/vendor/github.com/mattn/go-runewidth/runewidth.go
index 19f8e044..3d7fa560 100644
--- a/vendor/github.com/mattn/go-runewidth/runewidth.go
+++ b/vendor/github.com/mattn/go-runewidth/runewidth.go
@@ -2,6 +2,8 @@ package runewidth
 
 import (
 	"os"
+
+	"github.com/rivo/uniseg"
 )
 
 //go:generate go run script/generate.go
@@ -10,11 +12,14 @@ var (
 	// EastAsianWidth will be set true if the current locale is CJK
 	EastAsianWidth bool
 
-	// ZeroWidthJoiner is flag to set to use UTR#51 ZWJ
-	ZeroWidthJoiner bool
+	// StrictEmojiNeutral should be set false if handle broken fonts
+	StrictEmojiNeutral bool = true
 
 	// DefaultCondition is a condition in current locale
-	DefaultCondition = &Condition{}
+	DefaultCondition = &Condition{
+		EastAsianWidth:     false,
+		StrictEmojiNeutral: true,
+	}
 )
 
 func init() {
@@ -30,7 +35,6 @@ func handleEnv() {
 	}
 	// update DefaultCondition
 	DefaultCondition.EastAsianWidth = EastAsianWidth
-	DefaultCondition.ZeroWidthJoiner = ZeroWidthJoiner
 }
 
 type interval struct {
@@ -85,63 +89,69 @@ var nonprint = table{
 
 // Condition have flag EastAsianWidth whether the current locale is CJK or not.
 type Condition struct {
-	EastAsianWidth  bool
-	ZeroWidthJoiner bool
+	EastAsianWidth     bool
+	StrictEmojiNeutral bool
 }
 
 // NewCondition return new instance of Condition which is current locale.
 func NewCondition() *Condition {
 	return &Condition{
-		EastAsianWidth:  EastAsianWidth,
-		ZeroWidthJoiner: ZeroWidthJoiner,
+		EastAsianWidth:     EastAsianWidth,
+		StrictEmojiNeutral: StrictEmojiNeutral,
 	}
 }
 
 // RuneWidth returns the number of cells in r.
 // See http://www.unicode.org/reports/tr11/
 func (c *Condition) RuneWidth(r rune) int {
-	switch {
-	case r < 0 || r > 0x10FFFF || inTables(r, nonprint, combining, notassigned):
-		return 0
-	case (c.EastAsianWidth && IsAmbiguousWidth(r)) || inTables(r, doublewidth):
-		return 2
-	default:
-		return 1
-	}
-}
-
-func (c *Condition) stringWidth(s string) (width int) {
-	for _, r := range []rune(s) {
-		width += c.RuneWidth(r)
-	}
-	return width
-}
-
-func (c *Condition) stringWidthZeroJoiner(s string) (width int) {
-	r1, r2 := rune(0), rune(0)
-	for _, r := range []rune(s) {
-		if r == 0xFE0E || r == 0xFE0F {
-			continue
+	// optimized version, verified by TestRuneWidthChecksums()
+	if !c.EastAsianWidth {
+		switch {
+		case r < 0x20 || r > 0x10FFFF:
+			return 0
+		case (r >= 0x7F && r <= 0x9F) || r == 0xAD: // nonprint
+			return 0
+		case r < 0x300:
+			return 1
+		case inTable(r, narrow):
+			return 1
+		case inTables(r, nonprint, combining):
+			return 0
+		case inTable(r, doublewidth):
+			return 2
+		default:
+			return 1
 		}
-		w := c.RuneWidth(r)
-		if r2 == 0x200D && inTables(r, emoji) && inTables(r1, emoji) {
-			if width < w {
-				width = w
-			}
-		} else {
-			width += w
+	} else {
+		switch {
+		case r < 0 || r > 0x10FFFF || inTables(r, nonprint, combining):
+			return 0
+		case inTable(r, narrow):
+			return 1
+		case inTables(r, ambiguous, doublewidth):
+			return 2
+		case !c.StrictEmojiNeutral && inTables(r, ambiguous, emoji, narrow):
+			return 2
+		default:
+			return 1
 		}
-		r1, r2 = r2, r
 	}
-	return width
 }
 
 // StringWidth return width as you can see
 func (c *Condition) StringWidth(s string) (width int) {
-	if c.ZeroWidthJoiner {
-		return c.stringWidthZeroJoiner(s)
+	g := uniseg.NewGraphemes(s)
+	for g.Next() {
+		var chWidth int
+		for _, r := range g.Runes() {
+			chWidth = c.RuneWidth(r)
+			if chWidth > 0 {
+				break // Our best guess at this point is to use the width of the first non-zero-width rune.
+			}
+		}
+		width += chWidth
 	}
-	return c.stringWidth(s)
+	return
 }
 
 // Truncate return string truncated with w cells
@@ -149,19 +159,25 @@ func (c *Condition) Truncate(s string, w int, tail string) string {
 	if c.StringWidth(s) <= w {
 		return s
 	}
-	r := []rune(s)
-	tw := c.StringWidth(tail)
-	w -= tw
-	width := 0
-	i := 0
-	for ; i < len(r); i++ {
-		cw := c.RuneWidth(r[i])
-		if width+cw > w {
+	w -= c.StringWidth(tail)
+	var width int
+	pos := len(s)
+	g := uniseg.NewGraphemes(s)
+	for g.Next() {
+		var chWidth int
+		for _, r := range g.Runes() {
+			chWidth = c.RuneWidth(r)
+			if chWidth > 0 {
+				break // See StringWidth() for details.
+			}
+		}
+		if width+chWidth > w {
+			pos, _ = g.Positions()
 			break
 		}
-		width += cw
+		width += chWidth
 	}
-	return string(r[0:i]) + tail
+	return s[:pos] + tail
 }
 
 // Wrap return string wrapped with w cells
@@ -169,7 +185,7 @@ func (c *Condition) Wrap(s string, w int) string {
 	width := 0
 	out := ""
 	for _, r := range []rune(s) {
-		cw := RuneWidth(r)
+		cw := c.RuneWidth(r)
 		if r == '\n' {
 			out += string(r)
 			width = 0
diff --git a/vendor/github.com/mattn/go-runewidth/runewidth_table.go b/vendor/github.com/mattn/go-runewidth/runewidth_table.go
index b27d77d8..e5d890c2 100644
--- a/vendor/github.com/mattn/go-runewidth/runewidth_table.go
+++ b/vendor/github.com/mattn/go-runewidth/runewidth_table.go
@@ -124,8 +124,10 @@ var ambiguous = table{
 	{0x1F18F, 0x1F190}, {0x1F19B, 0x1F1AC}, {0xE0100, 0xE01EF},
 	{0xF0000, 0xFFFFD}, {0x100000, 0x10FFFD},
 }
-var notassigned = table{
-	{0x27E6, 0x27ED}, {0x2985, 0x2986},
+var narrow = table{
+	{0x0020, 0x007E}, {0x00A2, 0x00A3}, {0x00A5, 0x00A6},
+	{0x00AC, 0x00AC}, {0x00AF, 0x00AF}, {0x27E6, 0x27ED},
+	{0x2985, 0x2986},
 }
 
 var neutral = table{