2004-08-03  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpimage-undo.[ch] (gimp_image_undo_can_compress):
	new function which checks if undo compression is possible:

	(1) is the image dirty? Fixes bug #148853.
	(2) is redo stack empty?
	(3) do both the passed undo object_type and undo_type
	    match the top undo item?

	Consistently name the GType and GimpUndoType passed to undo
	functions "object_type" and "undo_type" to avoid confusion.

	* app/actions/layers-commands.c
	* app/tools/gimpeditselectiontool.c
	* app/tools/gimptexttool.c
	* app/widgets/gimpitemtreeview.c
	* app/widgets/gimplayertreeview.c: use the new utility function
	instead of checking the above conditions manually.