diff --git a/ChangeLog b/ChangeLog
index 244674b35a..48195a0177 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2007-09-07  Michael Natterer  <mitch@gimp.org>
+
+	* app/base/tile-manager.c (read_pixel_data_1): use a temporary
+	variable to store the return value of tile_manager_get() instead
+	of assigning to tm->cached_tile directly to make sure
+	tm->cached_num and tm->cached_tile are always in a consistent
+	state (the requested tile might be invalid and needs to be
+	validated, which would call tile_manager_get() recursively, which
+	in turn would clear the cached tile). Fixes bug #472770.
+
 2007-09-06  Martin Nordholts  <martinn@svn.gnome.org>
 
 	* app/tools/gimprectangletool.c (gimp_rectangle_tool_auto_shrink):
diff --git a/app/base/tile-manager.c b/app/base/tile-manager.c
index eac097fe60..8f198e9f86 100644
--- a/app/base/tile-manager.c
+++ b/app/base/tile-manager.c
@@ -767,11 +767,25 @@ read_pixel_data_1 (TileManager *tm,
 
       if (num != tm->cached_num)    /* must fetch a new tile */
         {
+          Tile *tile;
+
           if (tm->cached_tile)
             tile_release (tm->cached_tile, FALSE);
 
+          tm->cached_num  = -1;
+          tm->cached_tile = NULL;
+
+          /*  use a temporary variable instead of assigning to
+           *  tm->cached_tile directly to make sure tm->cached_num
+           *  and tm->cached_tile are always in a consistent state.
+           *  (the requested tile might be invalid and needs to be
+           *  validated, which would call tile_manager_get() recursively,
+           *  which in turn would clear the cached tile) See bug #472770.
+           */
+          tile = tile_manager_get (tm, num, TRUE, FALSE);
+
           tm->cached_num  = num;
-          tm->cached_tile = tile_manager_get (tm, num, TRUE, FALSE);
+          tm->cached_tile = tile;
         }
 
       if (tm->cached_tile)