We currently do not have a way to find out if power button was pressed in
application, which runs without root privileges (can't listen to sysevents).
gnome-power-manager used hal to do this, but we don't want to resurrect HAL support
in mate-power-manager. 

--- mate-power-manager-1.18.1/src/gpm-prefs-core.c.~3~	2018-01-17 16:15:43.600627799 +0000
+++ mate-power-manager-1.18.1/src/gpm-prefs-core.c	2018-01-17 16:23:56.595383559 +0000
@@ -658,6 +658,15 @@
 
 		gtk_widget_hide(widget);
 	}
+
+#if defined(__sun) && defined(__SVR4)
+	widget = GTK_WIDGET (gtk_builder_get_object (prefs->priv->builder, "hbox_general_power"));
+	gtk_widget_hide(widget);
+
+	/* After removing power button actions preferences "Actions" sections is empty, so we remove label */
+	widget = GTK_WIDGET (gtk_builder_get_object (prefs->priv->builder, "label122"));
+	gtk_widget_hide(widget);
+#endif
 }
 
 /**