Don't indent line if all we're outputting is ANSI sequences

ansiwriter.go

@@ -24,7 +24,7 @@ func (w *AnsiWriter) Write(b []byte) (int, error) {
 			w.ansiseq += string(c)
 		} else if w.ansi {
 			w.ansiseq += string(c)
-			if (c >= 0x40 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a) {
+			if (c >= 0x41 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a) {
 				// ANSI sequence terminated
 				w.ansi = false
 

indent.go

@@ -13,12 +13,23 @@ type IndentWriter struct {
 	IndentFunc IndentFunc
 
 	skipIndent bool
+	ansi       bool
 }
 
 // Write is used to write content to the indent buffer.
 func (w *IndentWriter) Write(b []byte) (int, error) {
 	for _, c := range string(b) {
+		if c == '\x1B' {
+			// ANSI escape sequence
+			w.ansi = true
+		} else if w.ansi {
+			if (c >= 0x41 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a) {
+				// ANSI sequence terminated
+				w.ansi = false
+			}
+		} else {
 			if !w.skipIndent {
+				w.Forward.ResetAnsi()
 				if w.IndentFunc != nil {
 					for i := 0; i < int(w.Indent); i++ {
 						w.IndentFunc(w.Forward)
@@ -30,15 +41,16 @@ func (w *IndentWriter) Write(b []byte) (int, error) {
 					}
 				}
 
-			w.Forward.RestoreAnsi()
 				w.skipIndent = true
+				w.Forward.RestoreAnsi()
 			}
 
 			if c == '\n' {
 				// end of current line
 				w.skipIndent = false
-			w.Forward.ResetAnsi()
 			}
+		}
+
 		_, err := w.Forward.Write([]byte(string(c)))
 		if err != nil {
 			return 0, err

padding.go

@@ -22,7 +22,7 @@ func (w *PaddingWriter) Write(b []byte) (int, error) {
 			// ANSI escape sequence
 			w.ansi = true
 		} else if w.ansi {
-			if (c >= 0x40 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a) {
+			if (c >= 0x41 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a) {
 				// ANSI sequence terminated
 				w.ansi = false
 				w.lineLen--