[evince] Resolves: rhbz#1404656 crash on opening second evince window

[Germán Poo-Caamaño <gpoo src gnome org>]

commit 62f6932337ca6d6139e82c96eb6b3aa10c05c386
Author: Caolán McNamara <caolanm redhat com>
Date:   Tue Jan 10 12:04:58 2017 +0000

    Resolves: rhbz#1404656 crash on opening second evince window
    
    e.g.
    
    export G_SLICE=always-malloc
    open https://www.antennahouse.com/XSLsample/pdf/sample-link_1.pdf
    right click on the first link and open in new window
    close the new window
    repeat
    crash
    
    This is similar to https://bugzilla.gnome.org/show_bug.cgi?id=726812
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777082

 shell/ev-window.c |   34 ++++++++++++++++++++++++----------
 1 files changed, 24 insertions(+), 10 deletions(-)
---
diff --git a/shell/ev-window.c b/shell/ev-window.c
index 06dcf25..f2f900b 100644
--- a/shell/ev-window.c
+++ b/shell/ev-window.c
@@ -6668,10 +6668,32 @@ _gtk_css_provider_load_from_resource (GtkCssProvider *provider,
 }
 
 static void
+ev_window_init_css (void)
+{
+       static gsize initialization_value = 0;
+
+       if (g_once_init_enter (&initialization_value)) {
+               GtkCssProvider *css_provider;
+               GError *error = NULL;
+
+               css_provider = gtk_css_provider_new ();
+               _gtk_css_provider_load_from_resource (css_provider,
+                                                     "/org/gnome/evince/ui/evince.css",
+                                                     &error);
+               g_assert_no_error (error);
+               gtk_style_context_add_provider_for_screen (gdk_screen_get_default (),
+                                               GTK_STYLE_PROVIDER (css_provider),
+                                               GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+               g_object_unref (css_provider);
+
+               g_once_init_leave (&initialization_value, 1);
+       }
+}
+
+static void
 ev_window_init (EvWindow *ev_window)
 {
        GtkBuilder *builder;
-       GtkCssProvider *css_provider;
        GError *error = NULL;
        GtkWidget *sidebar_widget;
        GtkWidget *overlay;
@@ -6751,15 +6773,7 @@ ev_window_init (EvWindow *ev_window)
                                         actions, G_N_ELEMENTS (actions),
                                         ev_window);
 
-       css_provider = gtk_css_provider_new ();
-       _gtk_css_provider_load_from_resource (css_provider,
-                                             "/org/gnome/evince/ui/evince.css",
-                                             &error);
-       g_assert_no_error (error);
-       gtk_style_context_add_provider_for_screen (gtk_widget_get_screen (GTK_WIDGET (ev_window)),
-                                       GTK_STYLE_PROVIDER (css_provider),
-                                       GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
-       g_object_unref (css_provider);
+       ev_window_init_css ();
 
        ev_window->priv->recent_manager = gtk_recent_manager_get_default ();