For security reasons we had to turn off the default fallback mechanism of the
MimeType, ExcludeMimeType,
IsCompressed and IsImage validators.
This means, that if the fileInfo or
magicMime extensions can not be found, the validation will
always fail.
If you are in need of validation by using the HTTP fields which
are provided by the user then you can turn on this feature by using the
enableHeaderCheck() method.
Security hint
You should note that relying on the HTTP fields, which are provided by your user, is a security risk. They can easily be changed and could allow your user to provide a malcious file.
Example 1056. Allow the usage of the HTTP fields
// at initiation
$valid = new Zend_File_Transfer_Adapter_Http(array('headerCheck' => true);
// or afterwards
$valid->enableHeaderCheck();