File cinnamon-session-fix-qt-themes.patch of Package cinnamon-session

--- a/cinnamon-session/main.c
+++ b/cinnamon-session/main.c
@@ -388,10 +388,8 @@ main (int argc, char **argv)
         /* Make QT5 apps follow the GTK style. Starting with QT 5.7, a different
          * env var has to be set than what worked in previous versions.
          */
-        qt_platform_theme_new = HAVE_QT57 ? "qt5ct" : "qgnomeplatform";
-
-        if (NULL == g_getenv ("QT_QPA_PLATFORMTHEME")) {
-            csm_util_setenv ("QT_QPA_PLATFORMTHEME", qt_platform_theme_new);
+        if (HAVE_QT57 && NULL == g_getenv ("QT_QPA_PLATFORMTHEME")) {
+            csm_util_setenv ("QT_QPA_PLATFORMTHEME", "gtk2");
         }
 
         if ( ! HAVE_QT57 && NULL == g_getenv ("QT_STYLE_OVERRIDE") ) {