Backport terminal-overflow from git-lfs#1806 to release-1.5

Author: ttaylorr

progress/meter.go

@@ -129,12 +129,6 @@ func (p *ProgressMeter) update() {
 		return
 	}
 
-	width := 80 // default to 80 chars wide if ts.GetSize() fails
-	size, err := ts.GetSize()
-	if err == nil {
-		width = size.Col()
-	}
-
 	// (%d of %d files, %d skipped) %f B / %f B, %f B skipped
 	// skipped counts only show when > 0
 
@@ -147,12 +141,7 @@ func (p *ProgressMeter) update() {
 		out += fmt.Sprintf(", %s skipped", formatBytes(p.skippedBytes))
 	}
 
-	padlen := width - len(out)
-	if 0 < padlen {
-		out += strings.Repeat(" ", padlen)
-	}
-
-	fmt.Fprintf(os.Stdout, out)
+	fmt.Fprintf(os.Stdout, pad(out))
 }
 
 func formatBytes(i int64) string {
@@ -169,3 +158,38 @@ func formatBytes(i int64) string {
 
 	return fmt.Sprintf("%d B", i)
 }
+
+const defaultWidth = 80
+
+// pad pads the given message to occupy the entire maximum width of the terminal
+// LFS is attached to. In doing so, this safeguards subsequent prints of shorter
+// messages from leaving stray characters from the previous message on the
+// screen by writing over them with whitespace padding.
+func pad(msg string) string {
+	width := defaultWidth
+	size, err := ts.GetSize()
+	if err == nil {
+		// If `ts.GetSize()` was successful, set the width to the number
+		// of columns present in the terminal LFS is attached to.
+		// Otherwise, fall-back to `defaultWidth`.
+		width = size.Col()
+	}
+
+	// Pad the string with whitespace so that printing at the start of the
+	// line removes all traces from the last print.removes all traces from
+	// the last print.
+	padding := strings.Repeat(" ", maxInt(0, width-len(msg)))
+
+	return msg + padding
+}
+
+// maxInt returns the greater of two `int`s, "a", or "b". This function
+// originally comes from `github.com/git-lfs/git-lfs/tools#MaxInt`, but would
+// introduce an import cycle if depended on directly.
+func maxInt(a, b int) int {
+	if a > b {
+		return a
+	}
+
+	return b
+}

progress/spinner.go

@@ -4,9 +4,6 @@ import (
 	"fmt"
 	"io"
 	"runtime"
-	"strings"
-
-	"github.com/olekukonko/ts"
 )
 
 // Indeterminate progress indicator 'spinner'
@@ -46,18 +43,7 @@ func (s *Spinner) Finish(out io.Writer, finishMsg string) {
 }
 
 func (s *Spinner) update(out io.Writer, prefix, msg string) {
-
-	str := fmt.Sprintf("%v %v", prefix, msg)
-
-	width := 80 // default to 80 chars wide if ts.GetSize() fails
-	size, err := ts.GetSize()
-	if err == nil {
-		width = size.Col()
-	}
-	padding := strings.Repeat(" ", width-len(str))
-
-	fmt.Fprintf(out, "\r%v%v", str, padding)
-
+	fmt.Fprintf(out, "\r%v", pad(fmt.Sprintf("%v %v", prefix, msg)))
 }
 
 func NewSpinner() *Spinner {