Only apply ui_style if it has changed

diff --git a/src/frontends/qt/GuiPrefs.cpp b/src/frontends/qt/GuiPrefs.cpp
index e72baf8f034c287a7ca08b2b6b3e7a11d49c6a77..a0c28e413f83e573af1bd30ed6a74405201f1fc7 100644 (file)
--- a/src/frontends/qt/GuiPrefs.cpp
+++ b/src/frontends/qt/GuiPrefs.cpp
@@ -2536,15 +2536,17 @@ void PrefUserInterface::applyRC(LyXRC & rc) const
 
        QString const uistyle = uiStyleCO->itemData(
                uiStyleCO->currentIndex()).toString();
-       rc.ui_style = fromqstr(uistyle);
-       if (rc.ui_style == "default")
-               // FIXME: This should work with frontend::GuiApplication::setStyle(QString())
-               //        Qt bug https://bugreports.qt.io/browse/QTBUG-58268
-               frontend::Alert::warning(_("Restart needed"),
-                                        _("Resetting the user interface style to 'Default'"
-                                          " requires a restart of LyX."));
-       else
-               frontend::GuiApplication::setStyle(uistyle);
+       if (rc.ui_style != fromqstr(uistyle)) {
+               rc.ui_style = fromqstr(uistyle);
+               if (rc.ui_style == "default")
+                       // FIXME: This should work with frontend::GuiApplication::setStyle(QString())
+                       //        Qt bug https://bugreports.qt.io/browse/QTBUG-58268
+                       frontend::Alert::warning(_("Restart needed"),
+                                                _("Resetting the user interface style to 'Default'"
+                                                  " requires a restart of LyX."));
+               else
+                       frontend::GuiApplication::setStyle(uistyle);
+       }
 
        rc.ui_file = internal_path(fromqstr(uiFileED->text()));
        rc.use_system_theme_icons = useSystemThemeIconsCB->isChecked();