I was using the latest Webkit Nightly when I noticed that Amazon.com's Gold Box Lightning Deals weren't rendering at all. This is on Leopard using a PowerPC G5. The error console displays the following:
ReferenceError: Strict mode forbids implicit creation of global property 'Deal'
According to smfr on #webkit IRC, the Lightning Deals box renders on Snow Leopard using a recent build, so this problem may be Leopard-only or even PowerPC-only.
Using the Webkit Nightly builds, I've narrowed down the regression to be between r69429 (which renders correctly) and r69611 (which renders incorrectly). Perhaps someone can use git-bisect or whatever to further narrow down the regression to a specific revision.
*** This bug has been marked as a duplicate of bug 48377 ***