check_curl: enable internal cookie handling

This enables us to enable curl cookie engine by specifying an empty
filename as the cookie jar file.

This works, since curl's CURLOPT_COOKIEFILE option allows passing an
empty string as filename, which it interprets as a request to enable the
cookie processing. But since CURLOPT_COOKIEJAR would now attempt to
write to a file named by an empty filename, it would break again (or at
least produce a warning in verbose output).

Overall this is allows to handle checking URLs with cookie based
sessions without persisting the cookies to disk, by using the
curl-internal redirect following.

0 files changed, 0 insertions, 0 deletions