Whitespace in front of an image suffix, such as "Foobar .jpg" (notice the space character before ".jpg"), should be stripped away by Special:Upload. It too confusing to distinguish between:
File:Foobar.jpg File:Foobar .jpg
etc.
after images are uploaded. The whitespace is usually a mistake anyway (in the original filename on the user's PC).
Right now, the whitespace is accepted as a valid
Version: 1.24rc
Severity: enhancement