Steps to reproduce:

1. In Chinese Wikipedia site's user preference, set "content language variant" to "zh-tw".
2. Search 花式滑冰 zh-tw page in Google: https://www.google.com/search?q=花式滑冰+wikipedia&lr=lang_zh-tw
3. Click the link to the article

Note: Navigate through google search is necessary for some reason. (maybe referer header)

Undesired behavior:

1. The browser history contains two entries of the Wikipedia article.
2. After clicking browser "go back", the the first page "javascript-redirect" to the second page, and the browser history again contains two pages. Thus a "redirect trap", that is, user cannot escape Wikipedia with "go back".