choose-fonts kitten: allow specifying the name of the conf file to edit

Fixes #7926

kittens/choose_fonts/final.go

@@ -35,7 +35,7 @@ func (self *final_pane) draw_screen() (err error) {
 		"",
 		"What would you like to do?",
 		"",
-		fmt.Sprintf("%s to modify %s and use the new fonts", h("Enter"), s("italic", `kitty.conf`)),
+		fmt.Sprintf("%s to modify %s and use the new fonts", h("Enter"), s("italic", self.handler.opts.Config_file_name)),
 		"",
 		fmt.Sprintf("%s to abort and return to font selection", h("Esc")),
 		"",
@@ -78,7 +78,12 @@ func (self *final_pane) on_key_event(event *loop.KeyEvent) (err error) {
 	if event.MatchesPressOrRepeat("enter") {
 		event.Handled = true
 		patcher := config.Patcher{Write_backup: true}
-		path := filepath.Join(utils.ConfigDir(), "kitty.conf")
+		path := ""
+		if filepath.IsAbs(self.handler.opts.Config_file_name) {
+			path = self.handler.opts.Config_file_name
+		} else {
+			path = filepath.Join(utils.ConfigDir(), self.handler.opts.Config_file_name)
+		}
 		updated, err := patcher.Patch(path, "KITTY_FONTS", self.settings.serialized(), "font_family", "bold_font", "italic_font", "bold_italic_font")
 		if err != nil {
 			return err

kittens/choose_fonts/main.go

@@ -68,7 +68,8 @@ func main(opts *Options) (rc int, err error) {
 }
 
 type Options struct {
-	Reload_in string
+	Reload_in        string
+	Config_file_name string
 }
 
 func EntryPoint(root *cli.Command) {
@@ -93,6 +94,18 @@ func EntryPoint(root *cli.Command) {
 running in to reload its config, after making changes. Use this option to
 instead either not reload the config at all or in all running kitty instances.`,
 	})
+	ans.Add(cli.OptionSpec{
+		Name:    "--config-file-name",
+		Dest:    "Config_file_name",
+		Type:    "str",
+		Default: "kitty.conf",
+		Help: `The name or path to the config file to edit. Relative paths are interpreted
+with respect to the kitty config directory. By default the kitty config
+file, kitty.conf is edited. This is most useful if you add include
+fonts.conf to your kitty.conf and then have the kitten operate only on
+fonts.conf, allowing kitty.conf to remain unchanged.`,
+	})
+
 	clone := root.AddClone(ans.Group, ans)
 	clone.Hidden = false
 	clone.Name = "choose_fonts"