In a breach of warranty lawsuit brought by plaintiff-clothing retailer, grant of summary judgment in favor of defendant is reversed where: 1) the trial court's interpretation of rightful claim was erroneous; 2) a rightful claim under section 2312(3) is a nonfrivolous claim of infringement that has any significant and adverse effect on the buyer's ability to make use of the purchased goods; and 3) under this standard, the trial court could not properly concluded, as a matter of law, that the third party infringement claim against plaintiff was not a rightful claim.