On our site we have a registration form that works almost all the time. Avatar image is required (using GD2 Libaray).
However in the last 8 hours we've had 4 people pass the validation check when uploading files with no extension... I assume they're mac users that don't really know anything about anything computer related and somehow managed to generate a image with no file-type extension. Does anyone have any tips on how to resolve this... Ideally it would be great if I could get the system to figure out the file type and write and extension to the file... In reality I would just love to see if anyone knows how I could go about filtering out any avatar image that doesn't contain an extension and throwing up the error message for image requirements.