diff -upr mate-control-center/font-viewer/font-model.c mate-control-center-test/font-viewer/font-model.c

--- mate-control-center/font-viewer/font-model.c	2015-08-30 12:49:57.333623654 +0200

+++ mate-control-center-test/font-viewer/font-model.c	2015-08-30 12:46:49.618704000 +0200

@@ -45,6 +45,7 @@

 struct _FontViewModelPrivate {

     /* list of fonts in fontconfig database */

     FcFontSet *font_list;

+    GMutex font_list_mutex;

     FT_Library library;

@@ -356,13 +357,15 @@ load_font_infos (GIOSchedulerJob *job,

 {

     FontViewModel *self = user_data;

     LoadFontInfosData *data;

-    gint i;

+    gint i, n_fonts;

     GList *font_infos = NULL;

     if (g_cancellable_is_cancelled (cancellable))

         return FALSE;

-    for (i = 0; i < self->priv->font_list->nfont; i++) {

+    n_fonts = self->priv->font_list->nfont;

+

+    for (i = 0; i < n_fonts; i++) {

         FontInfoData *font_info;

         FcChar8 *file;

         gchar *font_name;

@@ -370,7 +373,10 @@ load_font_infos (GIOSchedulerJob *job,

         if (g_cancellable_is_cancelled (cancellable))

             break;

-	FcPatternGetString (self->priv->font_list->fonts[i], FC_FILE, 0, &file);

+        g_mutex_lock (&self->priv->font_list_mutex);

+        FcPatternGetString (self->priv->font_list->fonts[i], FC_FILE, 0, &file);

+        g_mutex_unlock (&self->priv->font_list_mutex);

+

         font_name = font_utils_get_font_name_for_file (self->priv->library, (const gchar *) file);

         if (!font_name)

@@ -403,10 +409,9 @@ ensure_font_list (FontViewModel *self)

     FcPattern *pat;

     FcObjectSet *os;

-    if (self->priv->font_list) {

-        FcFontSetDestroy (self->priv->font_list);

-        self->priv->font_list = NULL;

-    }

+    /* always reinitialize the font database */

+    if (!FcInitReinitialize())

+        return;

     if (self->priv->cancellable) {

         g_cancellable_cancel (self->priv->cancellable);

@@ -415,21 +420,27 @@ ensure_font_list (FontViewModel *self)

     gtk_list_store_clear (GTK_LIST_STORE (self));

-    /* always reinitialize the font database */

-    if (!FcInitReinitialize())

-        return;

-

     pat = FcPatternCreate ();

     os = FcObjectSetBuild (FC_FILE, FC_FAMILY, FC_WEIGHT, FC_SLANT, NULL);

+    g_mutex_lock (&self->priv->font_list_mutex);

+

+    if (self->priv->font_list) {

+        FcFontSetDestroy (self->priv->font_list);

+        self->priv->font_list = NULL;

+    }

+

     self->priv->font_list = FcFontList (NULL, pat, os);

+    g_mutex_unlock (&self->priv->font_list_mutex);

+

     FcPatternDestroy (pat);

     FcObjectSetDestroy (os);

     if (!self->priv->font_list)

         return;

+    self->priv->cancellable = g_cancellable_new ();

     g_io_scheduler_push_job (load_font_infos, self, NULL,

                              G_PRIORITY_DEFAULT, self->priv->cancellable);

 }

@@ -547,6 +558,8 @@ font_view_model_init (FontViewModel *sel

     if (FT_Init_FreeType (&self->priv->library) != FT_Err_Ok)

         g_critical ("Can't initialize FreeType library");

+    g_mutex_init (&self->priv->font_list_mutex);

+

     gtk_list_store_set_column_types (GTK_LIST_STORE (self),

                                      NUM_COLUMNS, types);

@@ -576,8 +589,8 @@ font_view_model_finalize (GObject *obj)

     }

     if (self->priv->font_list) {

-            FcFontSetDestroy (self->priv->font_list);

-            self->priv->font_list = NULL;

+        FcFontSetDestroy (self->priv->font_list);

+        self->priv->font_list = NULL;

     }

     if (self->priv->library != NULL) {

@@ -585,6 +598,7 @@ font_view_model_finalize (GObject *obj)

         self->priv->library = NULL;

     }

+    g_mutex_clear (&self->priv->font_list_mutex);

     g_clear_object (&self->priv->fallback_icon);

     g_list_free_full (self->priv->monitors, (GDestroyNotify) g_object_unref);