Define required filename extraction.

src/zc/buildout/networkcache.txt

@@ -430,7 +430,9 @@ Buildout can download the content using the new certificate, because it still av
 ###############
 Check if the parsing url method works correctly, in low-level:
    >>> get_filename_from_url("http://localhost/lib/patch/?id=700c7d5382b01f94e7141")
-   'patch'
+   'id=700c7d5382b01f94e7141'
+   >>> get_filename_from_url("http://localhost/tarball-5.1.tar.gz?id=700")
+   'tarball-5.1.tar.gz'
 
 Check if the networkcache upload method is using the correct method to
 parse the original url and get the file name:
@@ -442,4 +444,4 @@ parse the original url and get the file name:
    ...                       external_url="http://localhost/lib/patch/?id=700c7d5382b01f94e7141",
    ...                       path=globals().get('tmp_dir') +  '/tmp_file',
    ...                       nc_server_path=sample_buildout)
-   'patch'
+   'id=700c7d5382b01f94e7141'