app: add XXX comments about hardcoded or NULL formats

app/core/gimpboundary.c

@@ -680,6 +680,7 @@ generate_boundary (GeglBuffer          *buffer,
 
   boundary = gimp_boundary_new (region);
 
+  /* XXX use an appropriate format here */
   format = gegl_buffer_get_format (buffer);
   bpp = babl_format_get_bytes_per_pixel (format);
 

app/core/gimpimage-crop.c

@@ -389,6 +389,7 @@ gimp_image_crop_auto_shrink (GimpImage *image,
   for (y = y1; y < y2 && !abort; y++)
     {
       rect.y = y;
+      /* XXX use an appropriate format here */
       gegl_buffer_get (buffer, &rect, 1.0, NULL, buf,
                        GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
       for (x = 0; x < width && !abort; x++)