$_FILES field 'tmp_name' has no value on .JPG file extension

Solution 1:

If $_FILES[$field]['tmp_name'] is empty then the file hasn't been uploaded. You should look at $_FILES[$field]['error'] to see why.

FWIW, and as far as I understand it, the mime-type in $_FILES[] is provided by the browser.

Update: here is a bit of potted code to handle all file upload errors:

        $message = 'Error uploading file';
        switch( $_FILES['newfile']['error'] ) {
            case UPLOAD_ERR_OK:
                $message = false;;
                break;
            case UPLOAD_ERR_INI_SIZE:
            case UPLOAD_ERR_FORM_SIZE:
                $message .= ' - file too large (limit of '.get_max_upload().' bytes).';
                break;
            case UPLOAD_ERR_PARTIAL:
                $message .= ' - file upload was not completed.';
                break;
            case UPLOAD_ERR_NO_FILE:
                $message .= ' - zero-length file uploaded.';
                break;
            default:
                $message .= ' - internal error #'.$_FILES['newfile']['error'];
                break;
        }
        if( !$message ) {
            if( !is_uploaded_file($_FILES['newfile']['tmp_name']) ) {
                $message = 'Error uploading file - unknown error.';
            } else {
                // Let's see if we can move the file...
                $dest .= '/'.$this_file;
                if( !move_uploaded_file($_FILES['newfile']['tmp_name'], $dest) ) { // No error supporession so we can see the underlying error.
                    $message = 'Error uploading file - could not save upload (this will probably be a permissions problem in '.$dest.')';
                } else {
                    $message = 'File uploaded okay.';
                }
            }
        }

Solution 2:

Check your php.ini and in particular this setting

; Maximum allowed size for uploaded files.
; http://www.php.net/manual/en/ini.core.php#ini.upload-max-filesize
upload_max_filesize = 6M

Or do this in your Apache Config:

<Directory "/var/www/vhosts/path/to/your/directory/import/">
    php_value post_max_size 6M
    php_value upload_max_filesize 6M
</Directory>

I would also say that it is poor that PHP doesn't report an error in the error logs if you upload a file that is larger than your php.ini upload_max_filesize setting. For example, if you upload a 6MB file when you have it set at 2M (which I think is the default).