[LOG] Fix double indirection for %% literal

Signed-off-by: Martino Facchin <[email protected]>

Author: facchinm

src/arduino.cc/builder/i18n/i18n.go

@@ -41,6 +41,7 @@ import (
 )
 
 var PLACEHOLDER = regexp.MustCompile("{(\\d)}")
+var LITERAL_PERCENT_SIGN = "_LITERAL_PERCENT_SIGN_"
 
 type Logger interface {
 	Fprintln(w io.Writer, level string, format string, a ...interface{})
@@ -61,11 +62,15 @@ func (s NoopLogger) Name() string {
 type HumanLogger struct{}
 
 func (s HumanLogger) Fprintln(w io.Writer, level string, format string, a ...interface{}) {
-	fmt.Fprintln(w, Format(format, a...))
+	msg := Format(format, a...)
+	// since fmt.Fprintln will be called without vardiadic arguments, drop the second %
+	msg = strings.Replace(msg, LITERAL_PERCENT_SIGN, "%", -1)
+	fmt.Fprintln(w, msg)
 }
 
 func (s HumanLogger) Println(level string, format string, a ...interface{}) {
-	s.Fprintln(os.Stdout, level, Format(format, a...))
+	msg := Format(format, a...)
+	s.Fprintln(os.Stdout, level, msg)
 }
 
 func (s HumanLogger) Name() string {
@@ -100,6 +105,7 @@ func (s MachineLogger) Name() string {
 
 func FromJavaToGoSyntax(s string) string {
 	submatches := PLACEHOLDER.FindAllStringSubmatch(s, -1)
+	s = strings.Replace(s, "%%", LITERAL_PERCENT_SIGN, -1)
 	for _, submatch := range submatches {
 		idx, err := strconv.Atoi(submatch[1])
 		if err != nil {