[evince] libview: Check number of pages when processing button events

[Carlos Garcia Campos <carlosgc src gnome org>]

commit f30aed7dbfb82a0d7d78f3c5c9b54f39b1316e6c
Author: Marek Kasik <mkasik redhat com>
Date:   Wed Aug 10 15:16:17 2016 +0200

    libview: Check number of pages when processing button events
    
    Check whether there are some pages in the opened document
    when processing button events to avoid crash.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769700

 libview/ev-view.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 2361958..9f0c866 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -4993,7 +4993,7 @@ ev_view_button_press_event (GtkWidget      *widget,
 {
        EvView *view = EV_VIEW (widget);
 
-       if (!view->document)
+       if (!view->document || ev_document_get_n_pages (view->document) <= 0)
                return FALSE;
 
        if (gtk_gesture_is_recognized (view->zoom_gesture))