Add DefaultLang config variable to set text/gemini lang parameter. Overridable via .molly file.

config.go

@@ -12,6 +12,7 @@ type Config struct {
 	DocBase            string
 	HomeDocBase        string
 	GeminiExt          string
+	DefaultLang        string
 	LogPath            string
 	TempRedirects      map[string]string
 	PermRedirects      map[string]string
@@ -21,6 +22,7 @@ type Config struct {
 
 type MollyFile struct {
 	GeminiExt          string
+	DefaultLang        string
 }
 
 func getConfig(filename string) (Config, error) {
@@ -35,6 +37,7 @@ func getConfig(filename string) (Config, error) {
 	config.DocBase = "/var/gemini/"
 	config.HomeDocBase = "users"
 	config.GeminiExt = "gmi"
+	config.DefaultLang = ""
 	config.LogPath = "molly.log"
 	config.TempRedirects = make(map[string]string)
 	config.PermRedirects = make(map[string]string)

handler.go

@@ -256,6 +256,9 @@ func parseMollyFiles(path string, info os.FileInfo, config *Config) {
 		if mollyFile.GeminiExt != "" {
 			config.GeminiExt = mollyFile.GeminiExt
 		}
+		if mollyFile.DefaultLang != "" {
+			config.DefaultLang = mollyFile.DefaultLang
+		}
 	}
 
 }
@@ -328,6 +331,10 @@ func serveFile(path string, log *LogEntry, conn net.Conn, config Config) {
 	} else {
 		mimeType = mime.TypeByExtension(ext)
 	}
+	// Add lang parameter
+	if mimeType == "text/gemini" && config.DefaultLang != "" {
+		mimeType += "; lang=" + config.DefaultLang
+	}
 	// Set a generic MIME type if the extension wasn't recognised
 	if mimeType == "" {
 		mimeType = "application/octet-stream"