From c2b1fd2df344c8262190e4b582692c7877eb861c Mon Sep 17 00:00:00 2001
From: James Antill <james@and.org>
Date: Sun, 8 Oct 2017 18:12:47 -0400
Subject: [PATCH 1/2] Ask terminal for width, use 80 columns by default on err.

---
 powerline.go | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/powerline.go b/powerline.go
index 8a92f5c1..50b64348 100644
--- a/powerline.go
+++ b/powerline.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"golang.org/x/crypto/ssh/terminal"
 	"golang.org/x/text/width"
 	"os"
 	"strconv"
@@ -75,10 +76,27 @@ func (p *powerline) appendSegment(origin string, segment segment) {
 	p.Segments = append(p.Segments, segment)
 }
 
+func termWidth() int {
+	width, _, err := terminal.GetSize(int(os.Stdout.Fd()))
+	if err != nil {
+		shellMaxLengthStr, found := os.LookupEnv("COLUMNS")
+		if !found {
+			return 80 // Otherwise 0 default.
+		}
+
+		shellMaxLength64, err := strconv.ParseInt(shellMaxLengthStr, 0, 64)
+		if err != nil {
+			return 80 // Otherwise 0 default.
+		}
+
+		width = int(shellMaxLength64)
+	}
+
+	return width
+}
+
 func (p *powerline) draw() string {
-	shellMaxLengthStr, _ := os.LookupEnv("COLUMNS")
-	shellMaxLength64, _ := strconv.ParseInt(shellMaxLengthStr, 0, 64)
-	shellMaxLength := int(shellMaxLength64)
+	shellMaxLength := termWidth()
 
 	shellMaxLength = shellMaxLength * *p.args.MaxWidthPercentage / 100
 

From 3dec992aa5dac4e5fb415ec7aa56f2c13387c12a Mon Sep 17 00:00:00 2001
From: James Antill <james@and.org>
Date: Mon, 16 Oct 2017 01:01:43 -0400
Subject: [PATCH 2/2] Import runewidth and use it instead of len(), to fix utf8
 problems.

---
 powerline.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/powerline.go b/powerline.go
index 50b64348..e8bbc0eb 100644
--- a/powerline.go
+++ b/powerline.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/mattn/go-runewidth"
 	"golang.org/x/crypto/ssh/terminal"
 	"golang.org/x/text/width"
 	"os"
@@ -102,8 +103,10 @@ func (p *powerline) draw() string {
 
 	shellActualLength := 0
 	if shellMaxLength > 0 {
+		rlen := runewidth.StringWidth
+
 		for _, segment := range p.Segments {
-			shellActualLength += len(segment.content) + len(segment.separator)
+			shellActualLength += rlen(segment.content) + rlen(segment.separator)
 		}
 		for shellActualLength > shellMaxLength {
 			minPriority := MaxInteger
@@ -117,7 +120,7 @@ func (p *powerline) draw() string {
 			if minPrioritySegmentId != -1 {
 				segment := p.Segments[minPrioritySegmentId]
 				p.Segments = append(p.Segments[:minPrioritySegmentId], p.Segments[minPrioritySegmentId+1:]...)
-				shellActualLength -= len(segment.content) + len(segment.separator)
+				shellActualLength -= rlen(segment.content) + rlen(segment.separator)
 			}
 		}
 	}