thodg/libgit2

diff --git a/src/transports/http.c b/src/transports/http.c
index 80ba5ba..9d77e62 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -1144,7 +1144,7 @@ static int http_stream_write_chunked(
 	const char *buffer,
 	size_t len)
 {
-	http_stream *s = (http_stream *)stream;
+	http_stream *s = GIT_CONTAINER_OF(stream, http_stream, parent);
 	http_subtransport *t = OWNING_SUBTRANSPORT(s);
 
 	assert(t->connected);
@@ -1218,7 +1218,7 @@ static int http_stream_write_single(
 	const char *buffer,
 	size_t len)
 {
-	http_stream *s = (http_stream *)stream;
+	http_stream *s = GIT_CONTAINER_OF(stream, http_stream, parent);
 	http_subtransport *t = OWNING_SUBTRANSPORT(s);
 	git_buf request = GIT_BUF_INIT;
 
@@ -1252,7 +1252,7 @@ on_error:
 
 static void http_stream_free(git_smart_subtransport_stream *stream)
 {
-	http_stream *s = (http_stream *)stream;
+	http_stream *s = GIT_CONTAINER_OF(stream, http_stream, parent);
 
 	if (s->chunk_buffer)
 		git__free(s->chunk_buffer);
@@ -1365,7 +1365,7 @@ static int http_action(
 	const char *url,
 	git_smart_service_t action)
 {
-	http_subtransport *t = (http_subtransport *)subtransport;
+	http_subtransport *t = GIT_CONTAINER_OF(subtransport, http_subtransport, parent);
 	int ret;
 
 	assert(stream);
@@ -1419,7 +1419,7 @@ static void free_auth_contexts(git_vector *contexts)
 
 static int http_close(git_smart_subtransport *subtransport)
 {
-	http_subtransport *t = (http_subtransport *) subtransport;
+	http_subtransport *t = GIT_CONTAINER_OF(subtransport, http_subtransport, parent);
 
 	clear_parser_state(t);
 
@@ -1459,7 +1459,7 @@ static int http_close(git_smart_subtransport *subtransport)
 
 static void http_free(git_smart_subtransport *subtransport)
 {
-	http_subtransport *t = (http_subtransport *) subtransport;
+	http_subtransport *t = GIT_CONTAINER_OF(subtransport, http_subtransport, parent);
 
 	http_close(subtransport);
 
diff --git a/src/transports/smart.c b/src/transports/smart.c
index fd7113c..7f66ae0 100644
--- a/src/transports/smart.c
+++ b/src/transports/smart.c
@@ -63,7 +63,7 @@ static int git_smart__set_callbacks(
 	git_transport_certificate_check_cb certificate_check_cb,
 	void *message_cb_payload)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	t->progress_cb = progress_cb;
 	t->error_cb = error_cb;
@@ -128,7 +128,7 @@ static int git_smart__set_custom_headers(
 	git_transport *transport,
 	const git_strarray *custom_headers)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	size_t i;
 
 	if (t->custom_headers.count)
@@ -212,7 +212,7 @@ static int git_smart__connect(
 	int direction,
 	int flags)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	git_smart_subtransport_stream *stream;
 	int error;
 	git_pkt *pkt;
@@ -315,7 +315,7 @@ cleanup:
 
 static int git_smart__ls(const git_remote_head ***out, size_t *size, git_transport *transport)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	if (!t->have_refs) {
 		git_error_set(GIT_ERROR_NET, "the transport has not yet loaded the refs");
@@ -330,7 +330,7 @@ static int git_smart__ls(const git_remote_head ***out, size_t *size, git_transpo
 
 int git_smart__negotiation_step(git_transport *transport, void *data, size_t len)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	git_smart_subtransport_stream *stream;
 	int error;
 
@@ -387,21 +387,21 @@ int git_smart__get_push_stream(transport_smart *t, git_smart_subtransport_stream
 
 static void git_smart__cancel(git_transport *transport)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	git_atomic_set(&t->cancelled, 1);
 }
 
 static int git_smart__is_connected(git_transport *transport)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	return t->connected;
 }
 
 static int git_smart__read_flags(git_transport *transport, int *flags)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	*flags = t->flags;
 
@@ -410,7 +410,7 @@ static int git_smart__read_flags(git_transport *transport, int *flags)
 
 static int git_smart__close(git_transport *transport)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	git_vector *common = &t->common;
 	unsigned int i;
 	git_pkt *p;
@@ -447,7 +447,7 @@ static int git_smart__close(git_transport *transport)
 
 static void git_smart__free(git_transport *transport)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	git_vector *refs = &t->refs;
 	unsigned int i;
 	git_pkt *p;
@@ -479,7 +479,7 @@ static int ref_name_cmp(const void *a, const void *b)
 
 int git_transport_smart_certificate_check(git_transport *transport, git_cert *cert, int valid, const char *hostname)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	assert(transport && cert && hostname);
 
@@ -491,7 +491,7 @@ int git_transport_smart_certificate_check(git_transport *transport, git_cert *ce
 
 int git_transport_smart_credentials(git_cred **out, git_transport *transport, const char *user, int methods)
 {
-	transport_smart *t = (transport_smart *)transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 
 	assert(out && transport);
 
@@ -503,7 +503,7 @@ int git_transport_smart_credentials(git_cred **out, git_transport *transport, co
 
 int git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport)
 {
-	transport_smart *t = (transport_smart *) transport;
+	transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 	return git_proxy_options_dup(out, &t->proxy);
 }
 
diff --git a/src/transports/ssh.c b/src/transports/ssh.c
index 5a6058f..9b5d8a5 100644
--- a/src/transports/ssh.c
+++ b/src/transports/ssh.c
@@ -132,7 +132,7 @@ static int ssh_stream_read(
 	size_t *bytes_read)
 {
 	int rc;
-	ssh_stream *s = (ssh_stream *)stream;
+	ssh_stream *s = GIT_CONTAINER_OF(stream, ssh_stream, parent);
 
 	*bytes_read = 0;
 
@@ -170,7 +170,7 @@ static int ssh_stream_write(
 	const char *buffer,
 	size_t len)
 {
-	ssh_stream *s = (ssh_stream *)stream;
+	ssh_stream *s = GIT_CONTAINER_OF(stream, ssh_stream, parent);
 	size_t off = 0;
 	ssize_t ret = 0;
 
@@ -196,7 +196,7 @@ static int ssh_stream_write(
 
 static void ssh_stream_free(git_smart_subtransport_stream *stream)
 {
-	ssh_stream *s = (ssh_stream *)stream;
+	ssh_stream *s = GIT_CONTAINER_OF(stream, ssh_stream, parent);
 	ssh_subtransport *t;
 
 	if (!stream)
@@ -479,7 +479,7 @@ static int _git_ssh_session_create(
 {
 	int rc = 0;
 	LIBSSH2_SESSION* s;
-	git_socket_stream *socket = (git_socket_stream *) io;
+	git_socket_stream *socket = GIT_CONTAINER_OF(io, git_socket_stream, parent);
 
 	assert(session);
 
@@ -730,7 +730,7 @@ static int _ssh_action(
 	const char *url,
 	git_smart_service_t action)
 {
-	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	ssh_subtransport *t = GIT_CONTAINER_OF(subtransport, ssh_subtransport, parent);
 
 	switch (action) {
 		case GIT_SERVICE_UPLOADPACK_LS:
@@ -752,7 +752,7 @@ static int _ssh_action(
 
 static int _ssh_close(git_smart_subtransport *subtransport)
 {
-	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	ssh_subtransport *t = GIT_CONTAINER_OF(subtransport, ssh_subtransport, parent);
 
 	assert(!t->current_stream);
 
@@ -763,7 +763,7 @@ static int _ssh_close(git_smart_subtransport *subtransport)
 
 static void _ssh_free(git_smart_subtransport *subtransport)
 {
-	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	ssh_subtransport *t = GIT_CONTAINER_OF(subtransport, ssh_subtransport, parent);
 
 	assert(!t->current_stream);