plumbing: diff, don't emit unnecessary resets

3 files changed, 24 insertions, 22 deletions

diff --git a/plumbing/format/diff/colorconfig.go b/plumbing/format/diff/colorconfig.go
index 1e72e7f..6fd4158 100644
--- a/plumbing/format/diff/colorconfig.go
+++ b/plumbing/format/diff/colorconfig.go
@@ -86,10 +86,11 @@ func NewColorConfig(options ...ColorConfigOption) ColorConfig {
 	return cc
 }
 
-// Reset returns the ANSI escape sequence to reset a color set from cc. If cc is
-// nil or empty then no reset is needed so it returns the empty string.
-func (cc ColorConfig) Reset() string {
-	if len(cc) == 0 {
+// Reset returns the ANSI escape sequence to reset the color with key set from
+// cc. If no color was set then no reset is needed so it returns the empty
+// string.
+func (cc ColorConfig) Reset(key ColorKey) string {
+	if cc[key] == "" {
 		return ""
 	}
 	return color.Reset
diff --git a/plumbing/format/diff/unified_encoder.go b/plumbing/format/diff/unified_encoder.go
index 6472db2..bd115f8 100644
--- a/plumbing/format/diff/unified_encoder.go
+++ b/plumbing/format/diff/unified_encoder.go
@@ -142,21 +142,21 @@ func (e *UnifiedEncoder) header(from, to File, isBinary bool) error {
 			e.pathLines(isBinary, aDir+from.Path(), bDir+to.Path())
 		}
 
-		e.buf.WriteString(e.color.Reset())
+		e.buf.WriteString(e.color.Reset(Meta))
 	case from == nil:
 		e.buf.WriteString(e.color[Meta])
 		fmt.Fprintf(&e.buf, diffInit, to.Path(), to.Path())
 		fmt.Fprintf(&e.buf, newFileMode, to.Mode())
 		fmt.Fprintf(&e.buf, indexNoMode, plumbing.ZeroHash, to.Hash())
 		e.pathLines(isBinary, noFilePath, bDir+to.Path())
-		e.buf.WriteString(e.color.Reset())
+		e.buf.WriteString(e.color.Reset(Meta))
 	case to == nil:
 		e.buf.WriteString(e.color[Meta])
 		fmt.Fprintf(&e.buf, diffInit, from.Path(), from.Path())
 		fmt.Fprintf(&e.buf, deletedFileMode, from.Mode())
 		fmt.Fprintf(&e.buf, indexNoMode, from.Hash(), plumbing.ZeroHash)
 		e.pathLines(isBinary, aDir+from.Path(), noFilePath)
-		e.buf.WriteString(e.color.Reset())
+		e.buf.WriteString(e.color.Reset(Meta))
 	}
 
 	return nil
@@ -338,13 +338,13 @@ func (c *hunk) WriteTo(buf *bytes.Buffer, color ColorConfig) {
 	}
 
 	buf.WriteString(chunkEnd)
-	buf.WriteString(color.Reset())
+	buf.WriteString(color.Reset(Frag))
 
 	if c.ctxPrefix != "" {
 		buf.WriteByte(' ')
 		buf.WriteString(color[Func])
 		buf.WriteString(c.ctxPrefix)
-		buf.WriteString(color.Reset())
+		buf.WriteString(color.Reset(Func))
 	}
 
 	buf.WriteByte('\n')
@@ -377,22 +377,23 @@ type op struct {
 }
 
 func (o *op) String(color ColorConfig) string {
-	var setColor, prefix, suffix string
+	var prefix, suffix string
+	var colorKey ColorKey
 	switch o.t {
 	case Add:
 		prefix = addLine
-		setColor = color[New]
+		colorKey = New
 	case Delete:
 		prefix = deleteLine
-		setColor = color[Old]
+		colorKey = Old
 	case Equal:
 		prefix = equalLine
-		setColor = color[Context]
+		colorKey = Context
 	}
 	n := len(o.text)
 	if n > 0 && o.text[n-1] != '\n' {
 		suffix = noNewLine
 	}
 
-	return fmt.Sprintf(prefix, setColor, o.text, color.Reset(), suffix)
+	return fmt.Sprintf(prefix, color[colorKey], o.text, color.Reset(colorKey), suffix)
 }
diff --git a/plumbing/format/diff/unified_encoder_test.go b/plumbing/format/diff/unified_encoder_test.go
index 83bc3c2..1e44572 100644
--- a/plumbing/format/diff/unified_encoder_test.go
+++ b/plumbing/format/diff/unified_encoder_test.go
@@ -896,7 +896,7 @@ index 0adddcde4fd38042c354518351820eb06c417c82..d39ae38aad7ba9447b5e7998b2e4714f
 		"--- a/README.md\n" +
 		"+++ b/README.md\n" + color.Reset +
 		color.Cyan + "@@ -1,2 +1,2 @@" + color.Reset + "\n" +
-		color.Normal + " hello\n" + color.Reset +
+		" hello\n" +
 		color.Red + "-world\n" + color.Reset +
 		color.Green + "+bug\n" + color.Reset,
 }, {
@@ -951,19 +951,19 @@ index 0adddcde4fd38042c354518351820eb06c417c82..d39ae38aad7ba9447b5e7998b2e4714f
 		"+++ b/onechunk.txt\n" + color.Reset +
 		color.Cyan + "@@ -1,2 +1 @@" + color.Reset + "\n" +
 		color.Red + "-A\n" + color.Reset +
-		color.Normal + " B\n" + color.Reset +
+		" B\n" +
 		color.Cyan + "@@ -7,3 +6,2 @@" + color.Reset + " " + color.Reverse + "F" + color.Reset + "\n" +
-		color.Normal + " G\n" + color.Reset +
+		" G\n" +
 		color.Red + "-H\n" + color.Reset +
-		color.Normal + " I\n" + color.Reset +
+		" I\n" +
 		color.Cyan + "@@ -14,3 +12,2 @@" + color.Reset + " " + color.Reverse + "M" + color.Reset + "\n" +
-		color.Normal + " N\n" + color.Reset +
+		" N\n" +
 		color.Red + "-Ñ\n" + color.Reset +
-		color.Normal + " O\n" + color.Reset +
+		" O\n" +
 		color.Cyan + "@@ -21,3 +18,2 @@" + color.Reset + " " + color.Reverse + "S" + color.Reset + "\n" +
-		color.Normal + " T\n" + color.Reset +
+		" T\n" +
 		color.Red + "-U\n" + color.Reset +
-		color.Normal + " V\n" + color.Reset,
+		" V\n",
 }}
 
 type testPatch struct {