file: fix incorrect multiline comment handling when write out (#157)

file.go

@@ -237,15 +237,20 @@ func (f *File) writeToBuffer(indent string) (*bytes.Buffer, error) {
 	for i, sname := range f.sectionList {
 		sec := f.Section(sname)
 		if len(sec.Comment) > 0 {
-			if sec.Comment[0] != '#' && sec.Comment[0] != ';' {
-				sec.Comment = "; " + sec.Comment
+			// Support multiline comments
+			lines := strings.Split(sec.Comment, LineBreak)
+			for i := range lines {
+				if lines[i][0] != '#' && lines[i][0] != ';' {
+					lines[i] = "; " + lines[i]
 				} else {
-				sec.Comment = sec.Comment[:1] + " " + strings.TrimSpace(sec.Comment[1:])
+					lines[i] = lines[i][:1] + " " + strings.TrimSpace(lines[i][1:])
 				}
-			if _, err := buf.WriteString(sec.Comment + LineBreak); err != nil {
+
+				if _, err := buf.WriteString(lines[i] + LineBreak); err != nil {
 					return nil, err
 				}
 			}
+		}
 
 		if i > 0 || DefaultHeader {
 			if _, err := buf.WriteString("[" + sname + "]" + LineBreak); err != nil {
@@ -300,19 +305,21 @@ func (f *File) writeToBuffer(indent string) (*bytes.Buffer, error) {
 				if len(indent) > 0 && sname != DEFAULT_SECTION {
 					buf.WriteString(indent)
 				}
-				if key.Comment[0] != '#' && key.Comment[0] != ';' {
-					key.Comment = "; " + key.Comment
-				} else {
-					key.Comment = key.Comment[:1] + " " + strings.TrimSpace(key.Comment[1:])
-				}
 
 				// Support multiline comments
-				key.Comment = strings.Replace(key.Comment, "\n", "\n; ", -1)
+				lines := strings.Split(key.Comment, LineBreak)
+				for i := range lines {
+					if lines[i][0] != '#' && lines[i][0] != ';' {
+						lines[i] = "; " + lines[i]
+					} else {
+						lines[i] = lines[i][:1] + " " + strings.TrimSpace(lines[i][1:])
+					}
 
-				if _, err := buf.WriteString(key.Comment + LineBreak); err != nil {
+					if _, err := buf.WriteString(lines[i] + LineBreak); err != nil {
 						return nil, err
 					}
 				}
+			}
 
 			if len(indent) > 0 && sname != DEFAULT_SECTION {
 				buf.WriteString(indent)

file_test.go

@@ -266,14 +266,27 @@ func TestFile_WriteTo(t *testing.T) {
 	})
 
 	Convey("Support multiline comments", t, func() {
-		f := ini.Empty()
+		f, err := ini.Load([]byte(`
+# 
+# general.domain
+# 
+# Domain name of XX system.
+domain      = mydomain.com
+`))
+		So(err, ShouldBeNil)
+
 		f.Section("").Key("test").Comment = "Multiline\nComment"
 
 		var buf bytes.Buffer
-		_, err := f.WriteTo(&buf)
+		_, err = f.WriteTo(&buf)
 		So(err, ShouldBeNil)
 
-		So(buf.String(), ShouldEqual, `; Multiline
+		So(buf.String(), ShouldEqual, `# 
+# general.domain
+# 
+# Domain name of XX system.
+domain = mydomain.com
+; Multiline
 ; Comment
 test   = 
 

ini.go

@@ -34,7 +34,7 @@ const (
 
 	// Maximum allowed depth when recursively substituing variable names.
 	_DEPTH_VALUES = 99
-	_VERSION      = "1.38.1"
+	_VERSION      = "1.38.2"
 )
 
 // Version returns current package version literal.