flickr: Only files with the following extensions are allowed ... when trying do get a flickr image.

I found the cause ... the filename contains a newline. I added code to

function filefield_source_remote_value($element, &$item) {

    $regex = '/\.('. preg_replace('/[ +]/', '|', preg_quote($extensions)) .')$/i';
dsm($regex, "'".$filename. "'");
    if (!empty($extensions) && !preg_match($regex, $filename)) {

to see the newline into the filename.

I suspect function _filefield_source_remote_filename() getting the newlined value from function filefield_source_remote_parse_header(&$ch, $header) { not checking for eol?

This image works http://www.budgetgaming.nl/plaatjes/reviews/flower/Flower_plaatje3.jpg

These image works too
- http://4.bp.blogspot.com/-KWHpPk4f-kM/TdZY_dxWMRI/AAAAAAAAADc/6FHVzBLY-4...
- http://i170.photobucket.com/albums/u244/30k-2007/contactsheet_red_flower...

So I changed the title to indicate flickr causing the newline.

Doing a curl --head http://4.bp.blogspot.com/-KWHpPk4f-kM/TdZY_dxWMRI/AAAAAAAAADc/6FHVzBLY-4o/s1600/flower-1.jpg results in

Content-Disposition: inline;filename="flower-1.jpg"

being the quoted variant. The flickr flow is through the unquoted preg_match

  elseif (preg_match('/Content-Disposition:.*?filename=([^; ]+)/', $header, $matches)) {
    // Content-Disposition: attachment; filename=file.ext
    _filefield_source_remote_filename($matches[1]);
  }

Refering http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html and http://www.ietf.org/rfc/rfc1806.txt suggest both regex could use some fine-tuning
- tokens are not case sensitive: inline, attachments (which is resolved by matching .*?)
- there could be more disposition params (not covered) which could follow a filename param

       disposition := "Content-Disposition" ":"
                       disposition-type
                       *(";" disposition-parm)

        disposition-type := "inline"
                          / "attachment"
                          / extension-token
                          ; values are not case-sensitive

        disposition-parm := filename-parm / parameter

        filename-parm := "filename" "=" value;

Anyways the patch is attached which is an ordinary trim.

See #1221382: Handle remote files without extensions based on Content-Type header which is seems a duplicate of this one.