diff -uprN mate-control-center/font-viewer/font-view.c mate-control-center-test/font-viewer/font-view.c

--- mate-control-center/font-viewer/font-view.c	2015-08-24 18:19:12.425945000 +0200

+++ mate-control-center-test/font-viewer/font-view.c	2015-08-24 19:10:24.180278977 +0200

@@ -249,23 +249,21 @@ static void

 install_button_refresh_appearance (FontViewApplication *self,

                                    GError *error)

 {

-    gchar *path;

+    FT_Face face;

     if (error != NULL) {

         gtk_button_set_label (GTK_BUTTON (self->install_button), _("Install Failed"));

         gtk_widget_set_sensitive (self->install_button, FALSE);

     } else {

-        path = g_file_get_path (self->font_file);

+        face = sushi_font_widget_get_ft_face (SUSHI_FONT_WIDGET (self->font_widget));

-        if (font_view_model_get_iter_for_file (FONT_VIEW_MODEL (self->model), path, NULL)) {

+        if (font_view_model_get_iter_for_face (FONT_VIEW_MODEL (self->model), face, NULL)) {

             gtk_button_set_label (GTK_BUTTON (self->install_button), _("Installed"));

             gtk_widget_set_sensitive (self->install_button, FALSE);

         } else {

             gtk_button_set_label (GTK_BUTTON (self->install_button), _("Install"));

             gtk_widget_set_sensitive (self->install_button, TRUE);

         }

-

-        g_free (path);

     }

 }

@@ -278,9 +276,10 @@ font_install_finished_cb (GObject      *

     GError *err = NULL;

     g_file_copy_finish (G_FILE (source_object), res, &err);

-    install_button_refresh_appearance (self, err);

     if (err != NULL) {

+        install_button_refresh_appearance (self, err);

+

         g_debug ("Install failed: %s", err->message);

         g_error_free (err);

     }

@@ -357,6 +356,8 @@ font_widget_loaded_cb (SushiFontWidget *

     gd_main_toolbar_set_labels (GD_MAIN_TOOLBAR (self->toolbar),

                                 face->family_name, face->style_name);

+

+    install_button_refresh_appearance (self, NULL);

 }

 static void

@@ -408,7 +409,6 @@ font_view_application_do_open (FontViewA

     self->install_button = gd_main_toolbar_add_button (GD_MAIN_TOOLBAR (self->toolbar),

                                                        NULL, _("Install"), 

                                                        FALSE);

-    install_button_refresh_appearance (self, NULL);

     g_signal_connect (self->install_button, "clicked",

                       G_CALLBACK (install_button_clicked_cb), self);