Internet auction site eBay has canceled the sale of an abstract painting that may have been an original by the late Richard Diebenkorn and barred the seller from its site after discovering he had bid on the painting himself. SACRAMENTO LAWYER Ken Walton sparked an art world controversy by accepting a $135,805 bid for the painting he allegedly found at a garage sale. Walton, who listed the painting under the name “Golfpoorly,” used a different alias to place a $4,500 bid on his own lot, a practice known as “shilling” aimed at prompting bidding wars among other participants, eBay said.