Userscripts.org

Hi, I've found that the URL expansion gets into infinity loop of calling LongUrlPlease API when it meets a certain kind of short URL in tweets, and it can cause browser freeze at the worst case.

Reproducible URLs are:
1. http://bit.ly/90ZgBP+
2. http://bit.ly/crossdomain.xml

The former URL is shrunk with bit.ly and added a analysis option "+". The LongUrlPlease API returns the following JSON response for this URL.

{"http:\/\/bit.ly\/90ZgBP ": null}

Function "expand_urls" cannot interpret the response because of two reasons:
- Short URL mismatch ("+" is replaced to " " at the end of URL)
- The long URL is set to null
As a result, the function goes into infinity loop and generates repeated API requests endlessly.

The latter URL is not shrunk but is a file on bit.ly itself. It also causes infinity loop after all. What's worse is that my Firefox gets unresponsive and frozen in this case.

As far as I can see, the solution might be:
- Remove additional options (such as "+") in the short URL
- Ignore invalid URL that doesn't seem to be shrunk
- Implement a limit count of calling API for each individual URL

Thank you for your great work and kind consideration.