Merge pull request #4318 from MichaelEischer/status-output-truncation

Fix status output truncation

changelog/unreleased/pull-4318

@@ -0,0 +1,8 @@
+Bugfix: Correctly clean up status bar output of the `backup` command
+
+Due to a regression in restic 0.15.2, the status bar of the `backup` command
+could leave some output behind. This happened if filenames were printed that
+are wider than the current terminal width. This has been fixed.
+
+https://github.com/restic/restic/issues/4319
+https://github.com/restic/restic/pull/4318

internal/ui/termstatus/status.go

@@ -334,6 +334,21 @@ func wideRune(s string) (wide bool, utfsize uint) {
 	return wide, uint(size)
 }
 
+func sanitizeLines(lines []string, width int) []string {
+	// Sanitize lines and truncate them if they're too long.
+	for i, line := range lines {
+		line = Quote(line)
+		if width > 0 {
+			line = Truncate(line, width-2)
+		}
+		if i < len(lines)-1 { // Last line gets no line break.
+			line += "\n"
+		}
+		lines[i] = line
+	}
+	return lines
+}
+
 // SetStatus updates the status lines.
 // The lines should not contain newlines; this method adds them.
 func (t *Terminal) SetStatus(lines []string) {
@@ -352,16 +367,7 @@ func (t *Terminal) SetStatus(lines []string) {
 		}
 	}
 
-	// Sanitize lines and truncate them if they're too long.
-	for i, line := range lines {
-		line = Quote(line)
-		if width > 0 {
-			line = Truncate(line, width-2)
-		}
-		if i < len(lines)-1 { // Last line gets no line break.
-			lines[i] = line + "\n"
-		}
-	}
+	sanitizeLines(lines, width)
 
 	select {
 	case t.status <- status{lines: lines}:

internal/ui/termstatus/status_test.go

@@ -1,12 +1,54 @@
 package termstatus
 
 import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
 	"strconv"
 	"testing"
 
 	rtest "github.com/restic/restic/internal/test"
 )
 
+func TestSetStatus(t *testing.T) {
+	var buf bytes.Buffer
+	term := New(&buf, io.Discard, false)
+
+	term.canUpdateStatus = true
+	term.fd = ^uintptr(0)
+	term.clearCurrentLine = posixClearCurrentLine
+	term.moveCursorUp = posixMoveCursorUp
+
+	ctx, cancel := context.WithCancel(context.Background())
+	go term.Run(ctx)
+
+	const (
+		clear = posixControlClearLine
+		home  = posixControlMoveCursorHome
+		up    = posixControlMoveCursorUp
+	)
+
+	term.SetStatus([]string{"first"})
+	exp := home + clear + "first" + home
+
+	term.SetStatus([]string{"foo", "bar", "baz"})
+	exp += home + clear + "foo\n" + home + clear + "bar\n" +
+		home + clear + "baz" + home + up + up
+
+	term.SetStatus([]string{"quux", "needs\nquote"})
+	exp += home + clear + "quux\n" +
+		home + clear + "\"needs\\nquote\"\n" +
+		home + clear + home + up + up // Third line implicit.
+
+	cancel()
+	exp += home + clear + "\n" + home + clear + "\n" +
+		home + up + up // Status cleared.
+
+	<-term.closed
+	rtest.Equals(t, exp, buf.String())
+}
+
 func TestQuote(t *testing.T) {
 	for _, c := range []struct {
 		in        string
@@ -91,3 +133,23 @@ func BenchmarkTruncateUnicode(b *testing.B) {
 
 	benchmarkTruncate(b, s, w-1)
 }
+
+func TestSanitizeLines(t *testing.T) {
+	var tests = []struct {
+		input  []string
+		width  int
+		output []string
+	}{
+		{[]string{""}, 80, []string{""}},
+		{[]string{"too long test line"}, 10, []string{"too long"}},
+		{[]string{"too long test line", "text"}, 10, []string{"too long\n", "text"}},
+		{[]string{"too long test line", "second long test line"}, 10, []string{"too long\n", "second l"}},
+	}
+
+	for _, test := range tests {
+		t.Run(fmt.Sprintf("%s %d", test.input, test.width), func(t *testing.T) {
+			out := sanitizeLines(test.input, test.width)
+			rtest.Equals(t, test.output, out)
+		})
+	}
+}