plumbing: config, support correct escaping as per git-config rules

2 files changed, 25 insertions, 13 deletions

diff --git a/plumbing/format/config/encoder.go b/plumbing/format/config/encoder.go
index 62921e0..de069ae 100644
--- a/plumbing/format/config/encoder.go
+++ b/plumbing/format/config/encoder.go
@@ -11,6 +11,10 @@ type Encoder struct {
 	w io.Writer
 }
 
+var (
+	subsectionReplacer = strings.NewReplacer(`"`, `\"`, `\`, `\\`)
+	valueReplacer = strings.NewReplacer(`"`, `\"`, `\`, `\\`, "\n", `\n`, "\t", `\t`, "\b", `\b`)
+)
 // NewEncoder returns a new encoder that writes to w.
 func NewEncoder(w io.Writer) *Encoder {
 	return &Encoder{w}
@@ -48,8 +52,7 @@ func (e *Encoder) encodeSection(s *Section) error {
 }
 
 func (e *Encoder) encodeSubsection(sectionName string, s *Subsection) error {
-	//TODO: escape
-	if err := e.printf("[%s \"%s\"]\n", sectionName, s.Name); err != nil {
+	if err := e.printf("[%s \"%s\"]\n", sectionName, subsectionReplacer.Replace(s.Name)); err != nil {
 		return err
 	}
 
@@ -58,12 +61,14 @@ func (e *Encoder) encodeSubsection(sectionName string, s *Subsection) error {
 
 func (e *Encoder) encodeOptions(opts Options) error {
 	for _, o := range opts {
-		pattern := "\t%s = %s\n"
-		if strings.ContainsAny(o.Value, `"#\`) || strings.HasPrefix(o.Value, " ") || strings.HasSuffix(o.Value, " ") {
-			pattern = "\t%s = %q\n"
+		var value string
+		if strings.ContainsAny(o.Value, "#;\"\t\n\\") || strings.HasPrefix(o.Value, " ") || strings.HasSuffix(o.Value, " ") {
+			value = `"`+valueReplacer.Replace(o.Value)+`"`
+		} else {
+			value = o.Value
 		}
 
-		if err := e.printf(pattern, o.Key, o.Value); err != nil {
+		if err := e.printf("\t%s = %s\n", o.Key, value); err != nil {
 			return err
 		}
 	}
diff --git a/plumbing/format/config/fixtures_test.go b/plumbing/format/config/fixtures_test.go
index 3255213..899ddf7 100644
--- a/plumbing/format/config/fixtures_test.go
+++ b/plumbing/format/config/fixtures_test.go
@@ -48,17 +48,24 @@ var fixtures = []*Fixture{
 	option1 = "has # hash"
 	option2 = "has \" quote"
 	option3 = "has \\ backslash"
-	option4 = "  has leading spaces"
-	option5 = "has trailing spaces  "
-	option6 = has no special characters
-`,
+	option4 = "has ; semicolon"
+	option5 = "has \n line-feed"
+	option6 = "has \t tab"
+	option7 = "  has leading spaces"
+	option8 = "has trailing spaces  "
+	option9 = has no special characters
+`+"\toption10 = has unusual \x01\x7f\xc8\x80 characters\n",
 		Config: New().
 			AddOption("section", "", "option1", `has # hash`).
 			AddOption("section", "", "option2", `has " quote`).
 			AddOption("section", "", "option3", `has \ backslash`).
-			AddOption("section", "", "option4", `  has leading spaces`).
-			AddOption("section", "", "option5", `has trailing spaces  `).
-			AddOption("section", "", "option6", `has no special characters`),
+			AddOption("section", "", "option4", `has ; semicolon`).
+			AddOption("section", "", "option5", "has \n line-feed").
+			AddOption("section", "", "option6", "has \t tab").
+			AddOption("section", "", "option7", `  has leading spaces`).
+			AddOption("section", "", "option8", `has trailing spaces  `).
+			AddOption("section", "", "option9", `has no special characters`).
+			AddOption("section", "", "option10", "has unusual \x01\x7f\u0200 characters"),
 	},
 	{
 		Raw: `