updated for version 7.3.985
Problem:    GTK vim not started as gvim doesn't set WM_CLASS property to a
            useful value.
Solution:   Call g_set_prgname() on startup. (James McCoy)
diff --git a/src/gui_gtk_x11.c b/src/gui_gtk_x11.c
index ceade75..853947c 100644
--- a/src/gui_gtk_x11.c
+++ b/src/gui_gtk_x11.c
@@ -1447,6 +1447,11 @@
 	using_gnome = 1;
 #endif
 
+    /* This defaults to argv[0], but we want it to match the name of the
+     * shipped gvim.desktop so that Vim's windows can be associated with this
+     * file. */
+    g_set_prgname("gvim");
+
     /* Don't use gtk_init() or gnome_init(), it exits on failure. */
     if (!gtk_init_check(&gui_argc, &gui_argv))
     {