transport: provide a getter for the proxy options

As with the callbacks, third-party implementations of smart subtransports cannot
reach into the opaque struct and thus cannot know what options the user set.

Add a getter for these options to copy the proxy options into something external
implementors can use.

Author: carlosmn

include/git2/sys/transport.h

@@ -241,6 +241,16 @@ GIT_EXTERN(int) git_transport_smart_certificate_check(git_transport *transport,
  */
 GIT_EXTERN(int) git_transport_smart_credentials(git_cred **out, git_transport *transport, const char *user, int methods);
 
+/**
+ * Get a copy of the proxy options
+ *
+ * The url is copied and must be freed by the caller.
+ *
+ * @param out options struct to fill
+ * @param transport the transport to extract the data from.
+ */
+GIT_EXTERN(int) git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport);
+
 /*
  *** End of base transport interface ***
  *** Begin interface for subtransports for the smart transport ***

src/transports/smart.c

@@ -472,6 +472,12 @@ int git_transport_smart_credentials(git_cred **out, git_transport *transport, co
 	return t->cred_acquire_cb(out, t->url, user, methods, t->cred_acquire_payload);
 }
 
+int git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport)
+{
+	transport_smart *t = (transport_smart *) transport;
+	return git_proxy_options_dup(out, &t->proxy);
+}
+
 int git_transport_smart(git_transport **out, git_remote *owner, void *param)
 {
 	transport_smart *t;