Keep certificate-directory problems on the station window and leave a hand-edit untouched until Save.

Co-authored-by: Cursor <cursoragent@cursor.com>

station/config_window.go

@@ -75,8 +75,19 @@ func (s *Station) Save(form ConfigForm) error {
 	s.logPath = next.logPath
 	s.logNotice = next.logNotice
 	reconnect := wasLoaded && connectionChanged(prev, next)
-	if reconnect || !wasLoaded {
-		s.fatal = ""
+	if next.certFatal != "" {
+		s.fatal = next.certFatal
+		s.closeLogLocked()
+		if next.enableLogging {
+			s.openLog()
+		}
+		if wasLoaded {
+			s.kickReconnect()
+		}
+	} else if reconnect || !wasLoaded {
+		if !wasLoaded || s.fatal == prev.certFatal {
+			s.fatal = ""
+		}
 		s.closeLogLocked()
 		if next.enableLogging {
 			s.openLog()
@@ -98,7 +109,8 @@ func (s *Station) kickReconnect() {
 		s.cancelDial()
 	}
 	if s.conn != nil {
-		s.conn.Close()
+		// Close unblocks the session read so Run can dial again.
+		_ = s.conn.Close()
 	}
 	select {
 	case s.apply <- struct{}{}:
@@ -139,7 +151,7 @@ func readForm(path string) (ConfigForm, string, bool) {
 		}
 		return form, fmt.Errorf("the file could not be read: %w", err).Error(), false
 	}
-	out, err := parseConfig(path, body)
+	out, err := parseConfig(path, body, false)
 	if err != nil {
 		return out.form, err.Error(), false
 	}
@@ -170,9 +182,6 @@ func validateForm(configPath string, form ConfigForm) (loaded, ConfigForm, error
 		return loaded{}, form, err
 	}
 	cfg = applyCertificate(cfg, shape, configPath)
-	if cfg.certFatal != "" {
-		return loaded{}, form, errors.New(cfg.certFatal)
-	}
 	cfg = applyLog(cfg, shape)
 	stored := ConfigForm{
 		Host:           cfg.host,
@@ -272,11 +281,16 @@ func createExclusive(path string, body []byte) error {
 	}
 	_, werr := f.Write(body)
 	cerr := f.Close()
-	if werr != nil {
-		return werr
-	}
-	if cerr != nil {
+	if werr != nil || cerr != nil {
+		os.Remove(path)
+		if werr != nil {
+			return werr
+		}
 		return cerr
 	}
-	return os.Chmod(path, 0o600)
+	if err := os.Chmod(path, 0o600); err != nil {
+		os.Remove(path)
+		return err
+	}
+	return nil
 }