(http://curl.haxx.se/bug/view.cgi?id=1431750) helped me identify and fix two
different but related bugs:
1) Removing an easy handle from a multi handle before the transfer is done
could leave a connection in the connection cache for that handle that is
in a state that isn't suitable for re-use. A subsequent re-use could then
read from a NULL pointer and segfault.
2) When an easy handle was removed from the multi handle, there could be an
outstanding c-ares DNS name resolve request. When the response arrived,
it caused havoc since the connection struct it "belonged" to could've
been freed already.
Now Curl_done() is called when an easy handle is removed from a multi handle
pre-maturely (that is, before the transfer was complteted). Curl_done() also
makes sure to cancel all (if any) outstanding c-ares requests.
type to the already provided type CURLPROXY_SOCKS4.
I added a --socks4 option that works like the current --socks5 option but
instead use the socks4 protocol.
server configured in the system, the ares_init() call fails and thus
curl_easy_init() fails as well. This causes weird effects for people who use
numerical IP addresses only.
an app can use to let libcurl only connect to a remote host and then extract
the socket from libcurl. libcurl will then not attempt to do any transfer at
all after the connect is done.
with re-used FTP connections. If the second request on the same connection was
set not to fetch a "body", libcurl could get confused and consider it an
attempt to use a dead connection and would go acting mighty strange.
curl tool with --local-port. Plain and simply set the range of ports to bind
the local end of connections to. Implemented on to popular demand.
Not extensively tested. Please let me know how it works.
connection setup as a follow-redirect. It turns out 1) this fails when a FTP
connection is re-setup and 2) it does make the max-redirs counter behave
wrong. This fix was not verified since the reporter vanished, but I believe
this is the right fix nonetheless.