2004-10-20  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpdrawable.[ch]: added gimp_drawable_mask_intersect()
	which returns the same bounding box as gimp_drawable_mask_bounds(),
	but returns TRUE only if there is a non-empty intersection between
	the drawable and the selection, or no selection at all. It also
	returns the intersection as x,y,width,height instead of the
	eeky x1,y1,x2,y2.

	* app/core/gimp-edit.c
	* app/core/gimpdrawable-blend.c
	* app/core/gimpdrawable-bucket-fill.c
	* app/core/gimpdrawable-desaturate.c
	* app/core/gimpdrawable-equalize.c
	* app/core/gimpdrawable-histogram.c
	* app/core/gimpdrawable-invert.c
	* app/core/gimpdrawable-stroke.c
	* app/core/gimpimagemap.c
	* app/core/gimpselection.c
	* tools/pdbgen/pdb/color.pdb
	* tools/pdbgen/pdb/transform_tools.pdb: either switch from
	gimp_drawable_mask_bounds() to _intersect() or check the return
	values of _mask_bounds() manually to avoid operations on empty
	areas. Return successfully because it's a nop, not a failure.
	Fixes bug #155733 for the core.

	* app/pdb/color_cmds.c
	* app/pdb/transform_tools_cmds.c: regenerated.