[Windows] Single bar duplicates when exactly terminal width

[benmurden]

Running the IO example given here https://github.com/vbauerster/mpb/blob/master/_examples/io/main.go with some modifications to prepend a long name, I have reproduced an issue I'm having where bars get duplicated once they reach the edge of the terminal window.

Actual code

package main

import (
	"crypto/rand"
	"io"
	"io/ioutil"
	"time"

	"github.com/vbauerster/mpb/v5"
	"github.com/vbauerster/mpb/v5/decor"
)

func main() {
	var total int64 = 1024 * 1024 * 1024
	reader := io.LimitReader(rand.Reader, total)

	p := mpb.New(
		mpb.WithWidth(60),
		mpb.WithRefreshRate(180*time.Millisecond),
	)

	bar := p.AddBar(total, mpb.BarStyle("[=>-|"),
		mpb.PrependDecorators(
			decor.Name("This is a really long name. I'm sorry it's so long but that's just the way it goes sometimes. "),
			decor.CountersKibiByte("% .2f / % .2f"),
			decor.Percentage(decor.WCSyncSpace),
		),
		mpb.AppendDecorators(
			decor.EwmaETA(decor.ET_STYLE_GO, 90),
			decor.Name(" ] "),
			decor.EwmaSpeed(decor.UnitKiB, "% .2f", 60),
		),
	)

	// create proxy reader
	proxyReader := bar.ProxyReader(reader)
	defer proxyReader.Close()

	// copy from proxyReader, ignoring errors
	io.Copy(ioutil.Discard, proxyReader)

	p.Wait()
}

The bar is clearly flexing to fill available space, but is still one character too long, it seems. Shorter names do not produce this issue.

OS: Windows 10

[nektro]

potential dupe of #55

[benmurden]

While it seems that way on the surface, I think this is a subtle bug, because the bar is being shrunk to fit the terminal width, but still wraps. Looks like the final size needs to be one or two characters shorter.

[vbauerster]

Can you please check master branch? Should be fixed.

[benmurden]

@vbauerster Looks good over here with the master branch. Thanks so much for your time and effort on this.

[vbauerster]

Thank you for reporting as well. I'll bump version soon.