From 562d02dc43fff2cdca3d6be2f822667674dc3e79 Mon Sep 17 00:00:00 2001
From: Christian Rocha <christian@rocha.is>
Date: Mon, 8 Jun 2020 13:43:55 -0400
Subject: [PATCH] Properly truncate fullwidth/double-byte chars

---
 ui/pager.go |  5 ++---
 ui/stash.go | 10 ++--------
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/ui/pager.go b/ui/pager.go
index 3f0564b..da4e385 100644
--- a/ui/pager.go
+++ b/ui/pager.go
@@ -266,14 +266,13 @@ func pagerStatusBarView(b *strings.Builder, m pagerModel) {
 	if len(noteText) == 0 {
 		noteText = "(No title)"
 	}
-	noteText = truncate(" "+noteText+" ", max(
-		0,
+	noteText = truncate(" "+noteText+" ", max(0,
 		m.width-len(logoText)-len(percentText)-len(helpNoteText),
 	))
 
 	// Empty space
 	emptyCell := te.String(" ").Background(statusBarBg.Color()).String()
-	padding := max(0, m.width-len(logoText)-len(noteText)-len(percentText)-len(helpNoteText))
+	padding := max(0, m.width-len(logoText)-runewidth.StringWidth(noteText)-len(percentText)-len(helpNoteText))
 	emptySpace := strings.Repeat(emptyCell, padding)
 
 	fmt.Fprintf(b, "%s%s%s%s%s",
diff --git a/ui/stash.go b/ui/stash.go
index a4e476a..7ad09be 100644
--- a/ui/stash.go
+++ b/ui/stash.go
@@ -14,6 +14,7 @@ import (
 	"github.com/charmbracelet/charm"
 	"github.com/charmbracelet/charm/ui/common"
 	"github.com/dustin/go-humanize"
+	runewidth "github.com/mattn/go-runewidth"
 	te "github.com/muesli/termenv"
 )
 
@@ -587,14 +588,7 @@ func wrapMarkdowns(t markdownType, md []*charm.Markdown) (m []*markdown) {
 }
 
 func truncate(str string, num int) string {
-	s := str
-	if len(str) > num {
-		if num > 1 {
-			num -= 1
-		}
-		s = str[0:num] + "…"
-	}
-	return s
+	return runewidth.Truncate(str, num, "…")
 }
 
 var magnitudes = []humanize.RelTimeMagnitude{