Hit a major bummer while updating the Punk widget today. Essentially, the onreadystatechange handler will miss the redirect/Location: (302) header being sent. IMDb uses 302 when there's only one search result and catching that was a really nice shortcut instead of having to parse the page to find out what has happened. The widget used curl before with which it's super-easy to notice these things, but for some other reasons, I had already re-written everything to use XMLHttpRequest.

Solutions? None so far, at least not for JavaScript. I think I've tried every possible way and place to stick getAllResponseHeaders(), including combining it with setTimeout(), but no cigar. The problem is, this behaviour is in the spec, so there's really no-one to blame. (?)

It really seems that, in my case, the “easiest” thing to do is just taking a peak at the page title. With IMDb it's easy - it's “IMDb Title Search” whenever there's more than 1 result.