diff --git a/ChangeLog b/ChangeLog
index 6290ced23..afba3cb0d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2008-10-20  Neil Roberts  <neil@linux.intel.com>
+
+	Bug 1043 - COGL calls glTexSubImage2D() with out-of-bounds
+	values (SIGSEGV)
+
+	* clutter/cogl/gl/cogl-texture.c
+	(_cogl_texture_upload_subregion_to_gl): When iterating over the
+	slices, discard ones that don't intersect immediatly otherwise it
+	will call glTexSubImage2D with a negative width/height and then
+	move the source position incorrectly. Thanks to Gwenole
+	Beauchesne.
+
 2008-10-20  Emmanuele Bassi  <ebassi@linux.intel.com>
 
 	* clutter/clutter-color.h: Declare clutter_color_new() in the
diff --git a/clutter/cogl/gl/cogl-texture.c b/clutter/cogl/gl/cogl-texture.c
index 101839e59..b4d8e7adc 100644
--- a/clutter/cogl/gl/cogl-texture.c
+++ b/clutter/cogl/gl/cogl-texture.c
@@ -395,6 +395,13 @@ _cogl_texture_upload_subregion_to_gl (CoglTexture *tex,
        _cogl_span_iter_next (&y_iter),
        source_y += inter_h )
     {
+      /* Discard slices out of the subregion early */
+      if (!y_iter.intersects)
+        {
+          inter_h = 0;
+          continue;
+        }
+
       /* Iterate horizontal spans */
       for (source_x = src_x,
 	   _cogl_span_iter_begin (&x_iter, tex->slice_x_spans,
@@ -406,6 +413,13 @@ _cogl_texture_upload_subregion_to_gl (CoglTexture *tex,
 	   _cogl_span_iter_next (&x_iter),
 	   source_x += inter_w )
         {
+	  /* Discard slices out of the subregion early */
+	  if (!x_iter.intersects)
+            {
+              inter_w = 0;
+              continue;
+            }
+
 	  /* Pick intersection width and height */
 	  inter_w = CLUTTER_FIXED_TO_INT (x_iter.intersect_end -
 					  x_iter.intersect_start);