2005-09-07  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpchannel-combine.c (gimp_channel_combine_ellipse):
	use gimp_rectangle_intersect() instead of just looking at the
	passed in w,h to figure whether nothing needs to be done. While
	the algorithm does nicely with an entirely out-of-image ellipse,
	the channel's bounds were set to a rectangle of zero width or
	height, which caused subsequent calls to gimp_channel_bounds() to
	return broken bounds. Fixes bug #315417.

	(gimp_channel_combine_rect)
	(gimp_channel_combine_mask): use gimp_rectangle_intersect() here
	too instead of the usual unclear CLAMPing on x1,y1,x2,y2.