'segmentation fault' when connection is closed before the internal redirect finish

Hi,

I had some problems of segmentation fault accessing upload context 
when the user closes the connection in the mean time the module is doing the redirect to the 'upload_pass' value.

To reproduce the problem you can change the example.php file in this way

- if ($_POST){
+ if ($_POST){
+   sleep(30);

after that, upload a small file, which takes less than 10 seconds to be uploaded, 
and after 10 seconds closes the connection (stop the loading or close the browser)

I hope this patch can be applied and help others.