Fix tdmtheme crash

This resolves Bug 1544
(cherry picked from commit 37dd210d31)

src/kdmtheme.cpp

@@ -268,6 +268,7 @@ void KDMThemeWidget::insertTheme( const TQString &_theme )
 
 void KDMThemeWidget::updateInfoView( ThemeData *theme )
 {
+	if(theme) {
 		info->setText(
 			((theme->copyright.length() > 0) ?
 				i18n("<qt><strong>Copyright:</strong> %1<br/></qt>",
@@ -277,7 +278,12 @@ void KDMThemeWidget::updateInfoView( ThemeData *theme )
 					theme->description) : "") );
 		preview->setPixmap( theme->path + '/' + theme->screenShot );
 		preview->setText( theme->screenShot.isEmpty() ?
-		"Screenshot not available" : TQString() );
+			i18n("Screenshot not available") : TQString() );
+	} else {
+		info->setText(i18n("No theme selected."));
+		preview->setPixmap(NULL);
+		preview->setText(i18n("Screenshot not available"));
+	}
 }
 
 void KDMThemeWidget::installNewTheme()