Currently upload-by-URL enforces $wgMaxUploadSize by counting up bytes as it downloads, then aborting when it reaches the maximum.
This could potentially be a long time... CURL should be able to give us the HTTP header values including any Content-Length header that may have been provided long before we get to this point, in which case we could abort immediately.
Ideally this ability should fold into Http class.
Version: unspecified
Severity: enhancement
URL: http://test.wikipedia.org/wiki/Special:Upload