[gegl] buffer: avoid inadvertently increasing revision of tile

[Ãyvind KolÃs <ok src gnome org>]

commit 3b983db51bc8743aed7ca30093423bf6686293aa
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Thu Mar 15 01:46:10 2012 +0000

    buffer: avoid inadvertently increasing revision of tile

 gegl/buffer/gegl-buffer.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer.c b/gegl/buffer/gegl-buffer.c
index b6b7179..555be78 100644
--- a/gegl/buffer/gegl-buffer.c
+++ b/gegl/buffer/gegl-buffer.c
@@ -742,6 +742,10 @@ gegl_buffer_get_tile (GeglTileSource *source,
             gegl_tile_lock (tile);
             tile->tile_storage = buffer->tile_storage;
             gegl_tile_unlock (tile);
+            tile->rev --; /* the lock/unlock cycle increases the revision
+                           * making it be out of sync with backing, causing
+                           * a save even of untouched images.
+                           */
           }
         tile->x = x;
         tile->y = y;