1 files changed, 364 insertions, 33 deletions

diff --git a/transport-helper.c b/transport-helper.c
index bfe3bc30a9..ca8fa92e63 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -6,6 +6,9 @@
 #include "diff.h"
 #include "revision.h"
 #include "quote.h"
+#include "remote.h"
+
+static int debug;
 
 struct helper_data
 {
@@ -13,15 +16,92 @@ struct helper_data
 	struct child_process *helper;
 	FILE *out;
 	unsigned fetch : 1,
+		import : 1,
 		option : 1,
-		push : 1;
+		push : 1,
+		connect : 1,
+		no_disconnect_req : 1;
+	/* These go from remote name (as in "list") to private name */
+	struct refspec *refspecs;
+	int refspec_nr;
+	/* Transport options for fetch-pack/send-pack (should one of
+	 * those be invoked).
+	 */
+	struct git_transport_options transport_options;
 };
 
+static void sendline(struct helper_data *helper, struct strbuf *buffer)
+{
+	if (debug)
+		fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
+	if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
+		!= buffer->len)
+		die_errno("Full write to remote helper failed");
+}
+
+static int recvline_fh(FILE *helper, struct strbuf *buffer)
+{
+	strbuf_reset(buffer);
+	if (debug)
+		fprintf(stderr, "Debug: Remote helper: Waiting...\n");
+	if (strbuf_getline(buffer, helper, '\n') == EOF) {
+		if (debug)
+			fprintf(stderr, "Debug: Remote helper quit.\n");
+		exit(128);
+	}
+
+	if (debug)
+		fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
+	return 0;
+}
+
+static int recvline(struct helper_data *helper, struct strbuf *buffer)
+{
+	return recvline_fh(helper->out, buffer);
+}
+
+static void xchgline(struct helper_data *helper, struct strbuf *buffer)
+{
+	sendline(helper, buffer);
+	recvline(helper, buffer);
+}
+
+static void write_constant(int fd, const char *str)
+{
+	if (debug)
+		fprintf(stderr, "Debug: Remote helper: -> %s", str);
+	if (write_in_full(fd, str, strlen(str)) != strlen(str))
+		die_errno("Full write to remote helper failed");
+}
+
+const char *remove_ext_force(const char *url)
+{
+	if (url) {
+		const char *colon = strchr(url, ':');
+		if (colon && colon[1] == ':')
+			return colon + 2;
+	}
+	return url;
+}
+
+static void do_take_over(struct transport *transport)
+{
+	struct helper_data *data;
+	data = (struct helper_data *)transport->data;
+	transport_take_over(transport, data->helper);
+	fclose(data->out);
+	free(data);
+}
+
 static struct child_process *get_helper(struct transport *transport)
 {
 	struct helper_data *data = transport->data;
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process *helper;
+	const char **refspecs = NULL;
+	int refspec_nr = 0;
+	int refspec_alloc = 0;
+	int duped;
 
 	if (data->helper)
 		return data->helper;
@@ -34,37 +114,91 @@ static struct child_process *get_helper(struct transport *transport)
 	strbuf_addf(&buf, "remote-%s", data->name);
 	helper->argv[0] = strbuf_detach(&buf, NULL);
 	helper->argv[1] = transport->remote->name;
-	helper->argv[2] = transport->url;
+	helper->argv[2] = remove_ext_force(transport->url);
 	helper->git_cmd = 1;
 	if (start_command(helper))
 		die("Unable to run helper: git %s", helper->argv[0]);
 	data->helper = helper;
+	data->no_disconnect_req = 0;
 
-	write_str_in_full(helper->in, "capabilities\n");
+	/*
+	 * Open the output as FILE* so strbuf_getline() can be used.
+	 * Do this with duped fd because fclose() will close the fd,
+	 * and stuff like taking over will require the fd to remain.
+	 */
+	duped = dup(helper->out);
+	if (duped < 0)
+		die_errno("Can't dup helper output fd");
+	data->out = xfdopen(duped, "r");
+
+	write_constant(helper->in, "capabilities\n");
 
-	data->out = xfdopen(helper->out, "r");
 	while (1) {
-		if (strbuf_getline(&buf, data->out, '\n') == EOF)
-			exit(128); /* child died, message supplied already */
+		const char *capname;
+		int mandatory = 0;
+		recvline(data, &buf);
 
 		if (!*buf.buf)
 			break;
-		if (!strcmp(buf.buf, "fetch"))
+
+		if (*buf.buf == '*') {
+			capname = buf.buf + 1;
+			mandatory = 1;
+		} else
+			capname = buf.buf;
+
+		if (debug)
+			fprintf(stderr, "Debug: Got cap %s\n", capname);
+		if (!strcmp(capname, "fetch"))
 			data->fetch = 1;
-		if (!strcmp(buf.buf, "option"))
+		else if (!strcmp(capname, "option"))
 			data->option = 1;
-		if (!strcmp(buf.buf, "push"))
+		else if (!strcmp(capname, "push"))
 			data->push = 1;
+		else if (!strcmp(capname, "import"))
+			data->import = 1;
+		else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
+			ALLOC_GROW(refspecs,
+				   refspec_nr + 1,
+				   refspec_alloc);
+			refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
+		} else if (!strcmp(capname, "connect")) {
+			data->connect = 1;
+		} else if (mandatory) {
+			die("Unknown madatory capability %s. This remote "
+			    "helper probably needs newer version of Git.\n",
+			    capname);
+		}
+	}
+	if (refspecs) {
+		int i;
+		data->refspec_nr = refspec_nr;
+		data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
+		for (i = 0; i < refspec_nr; i++) {
+			free((char *)refspecs[i]);
+		}
+		free(refspecs);
 	}
+	strbuf_release(&buf);
+	if (debug)
+		fprintf(stderr, "Debug: Capabilities complete.\n");
 	return data->helper;
 }
 
 static int disconnect_helper(struct transport *transport)
 {
 	struct helper_data *data = transport->data;
+	struct strbuf buf = STRBUF_INIT;
+
 	if (data->helper) {
-		write_str_in_full(data->helper->in, "\n");
+		if (debug)
+			fprintf(stderr, "Debug: Disconnecting.\n");
+		if (!data->no_disconnect_req) {
+			strbuf_addf(&buf, "\n");
+			sendline(data, &buf);
+		}
 		close(data->helper->in);
+		close(data->helper->out);
 		fclose(data->out);
 		finish_command(data->helper);
 		free((char *)data->helper->argv[0]);
@@ -72,7 +206,6 @@ static int disconnect_helper(struct transport *transport)
 		free(data->helper);
 		data->helper = NULL;
 	}
-	free(data);
 	return 0;
 }
 
@@ -92,10 +225,11 @@ static int set_helper_option(struct transport *transport,
 			  const char *name, const char *value)
 {
 	struct helper_data *data = transport->data;
-	struct child_process *helper = get_helper(transport);
 	struct strbuf buf = STRBUF_INIT;
 	int i, ret, is_bool = 0;
 
+	get_helper(transport);
+
 	if (!data->option)
 		return 1;
 
@@ -118,12 +252,7 @@ static int set_helper_option(struct transport *transport,
 		quote_c_style(value, &buf, NULL, 0);
 	strbuf_addch(&buf, '\n');
 
-	if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
-		die_errno("cannot send option to %s", data->name);
-
-	strbuf_reset(&buf);
-	if (strbuf_getline(&buf, data->out, '\n') == EOF)
-		exit(128); /* child died, message supplied already */
+	xchgline(data, &buf);
 
 	if (!strcmp(buf.buf, "ok"))
 		ret = 0;
@@ -154,8 +283,18 @@ static void standard_options(struct transport *t)
 	set_helper_option(t, "verbosity", buf);
 }
 
+static int release_helper(struct transport *transport)
+{
+	struct helper_data *data = transport->data;
+	free_refspec(data->refspec_nr, data->refspecs);
+	data->refspecs = NULL;
+	disconnect_helper(transport);
+	free(transport->data);
+	return 0;
+}
+
 static int fetch_with_fetch(struct transport *transport,
-			    int nr_heads, const struct ref **to_fetch)
+			    int nr_heads, struct ref **to_fetch)
 {
 	struct helper_data *data = transport->data;
 	int i;
@@ -173,13 +312,10 @@ static int fetch_with_fetch(struct transport *transport,
 	}
 
 	strbuf_addch(&buf, '\n');
-	if (write_in_full(data->helper->in, buf.buf, buf.len) != buf.len)
-		die_errno("cannot send fetch to %s", data->name);
+	sendline(data, &buf);
 
 	while (1) {
-		strbuf_reset(&buf);
-		if (strbuf_getline(&buf, data->out, '\n') == EOF)
-			exit(128); /* child died, message supplied already */
+		recvline(data, &buf);
 
 		if (!prefixcmp(buf.buf, "lock ")) {
 			const char *name = buf.buf + 5;
@@ -197,12 +333,169 @@ static int fetch_with_fetch(struct transport *transport,
 	return 0;
 }
 
+static int get_importer(struct transport *transport, struct child_process *fastimport)
+{
+	struct child_process *helper = get_helper(transport);
+	memset(fastimport, 0, sizeof(*fastimport));
+	fastimport->in = helper->out;
+	fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
+	fastimport->argv[0] = "fast-import";
+	fastimport->argv[1] = "--quiet";
+
+	fastimport->git_cmd = 1;
+	return start_command(fastimport);
+}
+
+static int fetch_with_import(struct transport *transport,
+			     int nr_heads, struct ref **to_fetch)
+{
+	struct child_process fastimport;
+	struct helper_data *data = transport->data;
+	int i;
+	struct ref *posn;
+	struct strbuf buf = STRBUF_INIT;
+
+	get_helper(transport);
+
+	if (get_importer(transport, &fastimport))
+		die("Couldn't run fast-import");
+
+	for (i = 0; i < nr_heads; i++) {
+		posn = to_fetch[i];
+		if (posn->status & REF_STATUS_UPTODATE)
+			continue;
+
+		strbuf_addf(&buf, "import %s\n", posn->name);
+		sendline(data, &buf);
+		strbuf_reset(&buf);
+	}
+	disconnect_helper(transport);
+	finish_command(&fastimport);
+	free(fastimport.argv);
+	fastimport.argv = NULL;
+
+	for (i = 0; i < nr_heads; i++) {
+		char *private;
+		posn = to_fetch[i];
+		if (posn->status & REF_STATUS_UPTODATE)
+			continue;
+		if (data->refspecs)
+			private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
+		else
+			private = strdup(posn->name);
+		read_ref(private, posn->old_sha1);
+		free(private);
+	}
+	strbuf_release(&buf);
+	return 0;
+}
+
+static int process_connect_service(struct transport *transport,
+				   const char *name, const char *exec)
+{
+	struct helper_data *data = transport->data;
+	struct strbuf cmdbuf = STRBUF_INIT;
+	struct child_process *helper;
+	int r, duped, ret = 0;
+	FILE *input;
+
+	helper = get_helper(transport);
+
+	/*
+	 * Yes, dup the pipe another time, as we need unbuffered version
+	 * of input pipe as FILE*. fclose() closes the underlying fd and
+	 * stream buffering only can be changed before first I/O operation
+	 * on it.
+	 */
+	duped = dup(helper->out);
+	if (duped < 0)
+		die_errno("Can't dup helper output fd");
+	input = xfdopen(duped, "r");
+	setvbuf(input, NULL, _IONBF, 0);
+
+	/*
+	 * Handle --upload-pack and friends. This is fire and forget...
+	 * just warn if it fails.
+	 */
+	if (strcmp(name, exec)) {
+		r = set_helper_option(transport, "servpath", exec);
+		if (r > 0)
+			warning("Setting remote service path not supported by protocol.");
+		else if (r < 0)
+			warning("Invalid remote service path.");
+	}
+
+	if (data->connect)
+		strbuf_addf(&cmdbuf, "connect %s\n", name);
+	else
+		goto exit;
+
+	sendline(data, &cmdbuf);
+	recvline_fh(input, &cmdbuf);
+	if (!strcmp(cmdbuf.buf, "")) {
+		data->no_disconnect_req = 1;
+		if (debug)
+			fprintf(stderr, "Debug: Smart transport connection "
+				"ready.\n");
+		ret = 1;
+	} else if (!strcmp(cmdbuf.buf, "fallback")) {
+		if (debug)
+			fprintf(stderr, "Debug: Falling back to dumb "
+				"transport.\n");
+	} else
+		die("Unknown response to connect: %s",
+			cmdbuf.buf);
+
+exit:
+	fclose(input);
+	return ret;
+}
+
+static int process_connect(struct transport *transport,
+				     int for_push)
+{
+	struct helper_data *data = transport->data;
+	const char *name;
+	const char *exec;
+
+	name = for_push ? "git-receive-pack" : "git-upload-pack";
+	if (for_push)
+		exec = data->transport_options.receivepack;
+	else
+		exec = data->transport_options.uploadpack;
+
+	return process_connect_service(transport, name, exec);
+}
+
+static int connect_helper(struct transport *transport, const char *name,
+		   const char *exec, int fd[2])
+{
+	struct helper_data *data = transport->data;
+
+	/* Get_helper so connect is inited. */
+	get_helper(transport);
+	if (!data->connect)
+		die("Operation not supported by protocol.");
+
+	if (!process_connect_service(transport, name, exec))
+		die("Can't connect to subservice %s.", name);
+
+	fd[0] = data->helper->out;
+	fd[1] = data->helper->in;
+	return 0;
+}
+
 static int fetch(struct transport *transport,
-		 int nr_heads, const struct ref **to_fetch)
+		 int nr_heads, struct ref **to_fetch)
 {
 	struct helper_data *data = transport->data;
 	int i, count;
 
+	if (process_connect(transport, 0)) {
+		do_take_over(transport);
+		return transport->fetch(transport, nr_heads, to_fetch);
+	}
+
 	count = 0;
 	for (i = 0; i < nr_heads; i++)
 		if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
@@ -214,6 +507,9 @@ static int fetch(struct transport *transport,
 	if (data->fetch)
 		return fetch_with_fetch(transport, nr_heads, to_fetch);
 
+	if (data->import)
+		return fetch_with_import(transport, nr_heads, to_fetch);
+
 	return -1;
 }
 
@@ -227,6 +523,11 @@ static int push_refs(struct transport *transport,
 	struct child_process *helper;
 	struct ref *ref;
 
+	if (process_connect(transport, 1)) {
+		do_take_over(transport);
+		return transport->push_refs(transport, remote_refs, flags);
+	}
+
 	if (!remote_refs)
 		return 0;
 
@@ -275,17 +576,14 @@ static int push_refs(struct transport *transport,
 	}
 
 	strbuf_addch(&buf, '\n');
-	if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
-		exit(128);
+	sendline(data, &buf);
 
 	ref = remote_refs;
 	while (1) {
 		char *refname, *msg;
 		int status;
 
-		strbuf_reset(&buf);
-		if (strbuf_getline(&buf, data->out, '\n') == EOF)
-			exit(128); /* child died, message supplied already */
+		recvline(data, &buf);
 		if (!buf.len)
 			break;
 
@@ -343,6 +641,22 @@ static int push_refs(struct transport *transport,
 	return 0;
 }
 
+static int has_attribute(const char *attrs, const char *attr) {
+	int len;
+	if (!attrs)
+		return 0;
+
+	len = strlen(attr);
+	for (;;) {
+		const char *space = strchrnul(attrs, ' ');
+		if (len == space - attrs && !strncmp(attrs, attr, len))
+			return 1;
+		if (!*space)
+			return 0;
+		attrs = space + 1;
+	}
+}
+
 static struct ref *get_refs_list(struct transport *transport, int for_push)
 {
 	struct helper_data *data = transport->data;
@@ -354,6 +668,11 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	helper = get_helper(transport);
 
+	if (process_connect(transport, for_push)) {
+		do_take_over(transport);
+		return transport->get_refs_list(transport, for_push);
+	}
+
 	if (data->push && for_push)
 		write_str_in_full(helper->in, "list for-push\n");
 	else
@@ -361,8 +680,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	while (1) {
 		char *eov, *eon;
-		if (strbuf_getline(&buf, data->out, '\n') == EOF)
-			exit(128); /* child died, message supplied already */
+		recvline(data, &buf);
 
 		if (!*buf.buf)
 			break;
@@ -379,8 +697,16 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 			(*tail)->symref = xstrdup(buf.buf + 1);
 		else if (buf.buf[0] != '?')
 			get_sha1_hex(buf.buf, (*tail)->old_sha1);
+		if (eon) {
+			if (has_attribute(eon + 1, "unchanged")) {
+				(*tail)->status |= REF_STATUS_UPTODATE;
+				read_ref((*tail)->name, (*tail)->old_sha1);
+			}
+		}
 		tail = &((*tail)->next);
 	}
+	if (debug)
+		fprintf(stderr, "Debug: Read ref listing.\n");
 	strbuf_release(&buf);
 
 	for (posn = ret; posn; posn = posn->next)
@@ -394,11 +720,16 @@ int transport_helper_init(struct transport *transport, const char *name)
 	struct helper_data *data = xcalloc(sizeof(*data), 1);
 	data->name = name;
 
+	if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
+		debug = 1;
+
 	transport->data = data;
 	transport->set_option = set_helper_option;
 	transport->get_refs_list = get_refs_list;
 	transport->fetch = fetch;
 	transport->push_refs = push_refs;
-	transport->disconnect = disconnect_helper;
+	transport->disconnect = release_helper;
+	transport->connect = connect_helper;
+	transport->smart_options = &(data->transport_options);
 	return 0;
 }