2003-07-29  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpimage.c (gimp_image_set_active_layer): moved the
	code which manipulates gimage->layer_stack and the call to
	gimp_layer_invalidate_boundary() inside the if(layer != active_layer)
	branch so it is called less often. Fixes the slowness of bug #104440
	for most cases since we don't need to recalculate the selection
	boundary in the next step.

	(gimp_image_set_active_channel): call
	gimp_layer_invalidate_boundary() before setting the active_layer
	to NULL. Fixes stale layer boundary when switching to a channel.

	* app/display/gimpdisplay.c (gimp_display_flush_whenever): when
	there are no updates, we still need to restart the selection.
	Fixes missing layer boundary when switching from a channel to
	a layer.