Remove unneeded check in *escapeInterpreter.parseOne()

escape.go

@@ -76,14 +76,16 @@ func (ei *escapeInterpreter) reset() {
 // of an escape sequence, and as such should not be printed verbatim. Otherwise,
 // it's not an escape sequence.
 func (ei *escapeInterpreter) parseOne(ch rune) (isEscape bool, err error) {
-	// Sanity checks to make sure we're not parsing something totally bogus.
+	// Sanity checks
 	if len(ei.csiParam) > 20 {
 		return false, errCSITooLong
 	}
 	if len(ei.csiParam) > 0 && len(ei.csiParam[len(ei.csiParam)-1]) > 255 {
 		return false, errCSITooLong
 	}
+
 	ei.curch = ch
+
 	switch ei.state {
 	case stateNone:
 		if ch == 0x1b {
@@ -117,16 +119,11 @@ func (ei *escapeInterpreter) parseOne(ch rune) (isEscape bool, err error) {
 			ei.csiParam = append(ei.csiParam, "")
 			return true, nil
 		case ch == 'm':
-			if len(ei.csiParam) < 1 {
-				return false, errCSIParseError
-			}
-
 			var err error
-
 			switch ei.mode {
-			case OutputMode(OutputNormal):
+			case OutputNormal:
 				err = ei.outputNormal()
-			case OutputMode(Output256):
+			case Output256:
 				err = ei.output256()
 			}
 			if err != nil {