[gthumb] crash after pressing shift-arrow

[Paolo Bacchilega <paobac src gnome org>]

commit bf15e0c8c42429713c7fd6974b28cf06cc058c93
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Jan 1 23:59:44 2016 +0100

    crash after pressing shift-arrow
    
    [bug #760050]

 gthumb/gth-grid-view.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gthumb/gth-grid-view.c b/gthumb/gth-grid-view.c
index 36a8e43..ec94f2f 100644
--- a/gthumb/gth-grid-view.c
+++ b/gthumb/gth-grid-view.c
@@ -3185,6 +3185,9 @@ select_range_with_keyboard (GthGridView *self,
        int    i;
        GList *link;
 
+       if (self->priv->focused_item == -1)
+               return;
+
        begin_idx = MIN (MIN (self->priv->first_focused_item, self->priv->focused_item), next_focused_item);
        end_idx = MAX (MAX (self->priv->first_focused_item, self->priv->focused_item), next_focused_item);
        begin = g_list_nth (self->priv->items, begin_idx);