[evince/gnome-3-12] Prevent jumps to last page when autoscrolling

[Marek Kašík <mkasik src gnome org>]

commit 2880a1b18b8c4713008d78e4d45022acc6b3dbb0
Author: Marek Kasik <mkasik redhat com>
Date:   Tue May 20 16:12:52 2014 +0200

    Prevent jumps to last page when autoscrolling
    
    It can happen during autoscrolling that current page is set to the last one
    when you are moving towards beginning of the document and crosses toolbar
    above the document.
    This happens due to filling of unsigned integer "scroll_info.last_y"
    with negative value.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=725389

 libview/ev-view.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 3970993..10bce7d 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -4961,7 +4961,8 @@ ev_view_motion_notify_event (GtkWidget      *widget,
        }
 
        if (view->scroll_info.autoscrolling) {
-               view->scroll_info.last_y = y;
+               if (y >= 0)
+                       view->scroll_info.last_y = y;
                return TRUE;
        }