[gegl] buffer: make linear open buffer test pass

[Øyvind Kolås <ok src gnome org>]

commit 5b9befe0cc936994452c4ef7eb791a3278d32e59
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jun 4 12:09:53 2014 +0200

    buffer: make linear open buffer test pass

 gegl/buffer/gegl-buffer-iterator.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-iterator.c b/gegl/buffer/gegl-buffer-iterator.c
index ce7edb8..969561f 100644
--- a/gegl/buffer/gegl-buffer-iterator.c
+++ b/gegl/buffer/gegl-buffer-iterator.c
@@ -548,9 +548,10 @@ static void linear_shortcut (GeglBufferIterator *iter)
       else
       {
         if (sub->buffer->tile_width == sub->buffer->extent.width 
-            && sub->buffer->tile_height == sub->buffer->extent.height)
+            && sub->buffer->tile_height == sub->buffer->extent.height
+            && sub->buffer->extent.x == iter->roi[index].x
+            && sub->buffer->extent.y == iter->roi[index].y)
         {
-          /* XXX: does this work correctly for coords? */
           get_tile (iter, index);
         }
         else