2004-01-18  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpimage.c (gimp_image_set_active_layer): don't allow
	to select anything but the floating selection. Fixes bug #128025.

	(gimp_image_set_active_layer,channel,vectors): allow to pass NULL
	to unselect the active item. Removed the silly feature that
	passing some random item of another image would select the first
	item in the list (was unused anyway).

	(gimp_image_unset_active_channel): use gimp_image_set_active_channel()
	now that it accepts NULL.

	(gimp_image_add_layer,channel,vectors): cleaned up / simplified.

	(gimp_image_remove_layer,channel,vectors): cleanup,
	simplification, use gimp_image_set_active_layer,channel,vectors()
	now that they accept NULL, make sure the item next to the removed
	item becomes the active one (and not the first in the list, which
	was a severe usability problem in the dialogs).

	* app/core/gimpimage-undo-push.c (undo_pop_layer,channel): pass
	NULL to the set_active functions, cleanup.

	* app/core/gimpimage-duplicate.c: attach the floating selection
	before setting the active layer. Code relied on broken
	gimp_image_set_active_layer() behaviour before.

	* app/core/gimplayer-floating-sel.c: no need to set
	gimage->floating_sel before calling gimp_image_add_layer(). The
	weird GUI mentioned in the comment existed in 1.2 only.

	* app/display/gimpdisplayshell-layer-select.c (layer_select_advance):
	don't assume that setting the active_layer always succeeds.

	* tools/pdbgen/pdb/image.pdb: behave as the documentation says
	and return an execution error if setting the active layer or
	channel failed.

	Unrelated:

	* tools/pdbgen/pdb/image.pdb
	* tools/pdbgen/pdb/layer.pdb: removed leftover cruft from the old
	guchar based color API.

	* tools/pdbgen/pdb/channel.pdb: simplified code which handles the
	channel's color.

	* app/pdb/channel_cmds.c
	* app/pdb/image_cmds.c: regenerated.