Merge branch 'fa/remote-svn'

A GSoC project.

* fa/remote-svn:
  Add a test script for remote-svn
  remote-svn: add marks-file regeneration
  Add a svnrdump-simulator replaying a dump file for testing
  remote-svn: add incremental import
  remote-svn: Activate import/export-marks for fast-import
  Create a note for every imported commit containing svn metadata
  vcs-svn: add fast_export_note to create notes
  Allow reading svn dumps from files via file:// urls
  remote-svn, vcs-svn: Enable fetching to private refs
  When debug==1, start fast-import with "--stats" instead of "--quiet"
  Add documentation for the 'bidi-import' capability of remote-helpers
  Connect fast-import to the remote-helper via pipe, adding 'bidi-import' capability
  Add argv_array_detach and argv_array_free_detached
  Add svndump_init_fd to allow reading dumps from arbitrary FDs
  Add git-remote-testsvn to Makefile
  Implement a remote helper for svn in C

16 files changed, 655 insertions, 38 deletions

diff --git a/.gitignore b/.gitignore
index a188a82bb..f702415c1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -125,6 +125,7 @@
 /git-remote-fd
 /git-remote-ext
 /git-remote-testgit
+/git-remote-testsvn
 /git-repack
 /git-replace
 /git-repo-config
diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index f5836e46d..5ce4cda8e 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -98,6 +98,20 @@ advertised with this capability must cover all refs reported by
 the list command.  If no 'refspec' capability is advertised,
 there is an implied `refspec *:*`.
 
+'bidi-import'::
+	The fast-import commands 'cat-blob' and 'ls' can be used by remote-helpers
+	to retrieve information about blobs and trees that already exist in
+	fast-import's memory. This requires a channel from fast-import to the
+	remote-helper.
+	If it is advertised in addition to "import", git establishes a pipe from
+	fast-import to the remote-helper's stdin.
+	It follows that git and fast-import are both connected to the
+	remote-helper's stdin. Because git can send multiple commands to
+	the remote-helper it is required that helpers that use 'bidi-import'
+	buffer all 'import' commands of a batch before sending data to fast-import.
+	This is to prevent mixing commands and fast-import responses on the
+	helper's stdin.
+
 Capabilities for Pushing
 ~~~~~~~~~~~~~~~~~~~~~~~~
 'connect'::
@@ -286,7 +300,12 @@ terminated with a blank line. For each batch of 'import', the remote
 helper should produce a fast-import stream terminated by a 'done'
 command.
 +
-Supported if the helper has the "import" capability.
+Note that if the 'bidi-import' capability is used the complete batch
+sequence has to be buffered before starting to send data to fast-import
+to prevent mixing of commands and fast-import responses on the helper's
+stdin.
++
+Supported if the helper has the 'import' capability.
 
 'connect' <service>::
 	Connects to given service. Standard input and standard output
diff --git a/Documentation/technical/api-argv-array.txt b/Documentation/technical/api-argv-array.txt
index 1a797812f..a959517b2 100644
--- a/Documentation/technical/api-argv-array.txt
+++ b/Documentation/technical/api-argv-array.txt
@@ -53,3 +53,11 @@ Functions
 `argv_array_clear`::
 	Free all memory associated with the array and return it to the
 	initial, empty state.
+
+`argv_array_detach`::
+	Detach the argv array from the `struct argv_array`, transfering
+	ownership of the allocated array and strings.
+
+`argv_array_free_detached`::
+	Free the memory allocated by a `struct argv_array` that was later
+	detached and is now no longer needed.
diff --git a/Makefile b/Makefile
index f69979e39..40829a9e9 100644
--- a/Makefile
+++ b/Makefile
@@ -495,6 +495,7 @@ PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
 PROGRAM_OBJS += show-index.o
 PROGRAM_OBJS += upload-pack.o
+PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
 X =
@@ -2449,6 +2450,10 @@ git-http-push$X: revision.o http.o http-push.o GIT-LDFLAGS $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
+git-remote-testsvn$X: remote-testsvn.o GIT-LDFLAGS $(GITLIBS) $(VCSSVN_LIB)
+	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS) \
+	$(VCSSVN_LIB)
+
 $(REMOTE_CURL_ALIASES): $(REMOTE_CURL_PRIMARY)
 	$(QUIET_LNCP)$(RM) $@ && \
 	ln $< $@ 2>/dev/null || \
diff --git a/argv-array.c b/argv-array.c
index 256741d22..9e960d549 100644
--- a/argv-array.c
+++ b/argv-array.c
@@ -68,3 +68,23 @@ void argv_array_clear(struct argv_array *array)
 	}
 	argv_array_init(array);
 }
+
+const char **argv_array_detach(struct argv_array *array, int *argc)
+{
+	const char **argv =
+		array->argv == empty_argv || array->argc == 0 ? NULL : array->argv;
+	if (argc)
+		*argc = array->argc;
+	argv_array_init(array);
+	return argv;
+}
+
+void argv_array_free_detached(const char **argv)
+{
+	if (argv) {
+		int i;
+		for (i = 0; argv[i]; i++)
+			free((char **)argv[i]);
+		free(argv);
+	}
+}
diff --git a/argv-array.h b/argv-array.h
index f4b98660f..40248d424 100644
--- a/argv-array.h
+++ b/argv-array.h
@@ -18,5 +18,7 @@ void argv_array_pushf(struct argv_array *, const char *fmt, ...);
 void argv_array_pushl(struct argv_array *, ...);
 void argv_array_pop(struct argv_array *);
 void argv_array_clear(struct argv_array *);
+const char **argv_array_detach(struct argv_array *array, int *argc);
+void argv_array_free_detached(const char **argv);
 
 #endif /* ARGV_ARRAY_H */
diff --git a/contrib/svn-fe/svn-fe.c b/contrib/svn-fe/svn-fe.c
index 35db24f5e..f363505ab 100644
--- a/contrib/svn-fe/svn-fe.c
+++ b/contrib/svn-fe/svn-fe.c
@@ -10,7 +10,8 @@ int main(int argc, char **argv)
 {
 	if (svndump_init(NULL))
 		return 1;
-	svndump_read((argc > 1) ? argv[1] : NULL);
+	svndump_read((argc > 1) ? argv[1] : NULL, "refs/heads/master",
+			"refs/notes/svn/revs");
 	svndump_deinit();
 	svndump_reset();
 	return 0;
diff --git a/contrib/svn-fe/svnrdump_sim.py b/contrib/svn-fe/svnrdump_sim.py
new file mode 100755
index 000000000..1cfac4a6f
--- /dev/null
+++ b/contrib/svn-fe/svnrdump_sim.py
@@ -0,0 +1,53 @@
+#!/usr/bin/python
+"""
+Simulates svnrdump by replaying an existing dump from a file, taking care
+of the specified revision range.
+To simulate incremental imports the environment variable SVNRMAX can be set
+to the highest revision that should be available.
+"""
+import sys, os
+
+
+def getrevlimit():
+        var = 'SVNRMAX'
+        if os.environ.has_key(var):
+                return os.environ[var]
+        return None
+
+def writedump(url, lower, upper):
+        if url.startswith('sim://'):
+                filename = url[6:]
+                if filename[-1] == '/': filename = filename[:-1] #remove terminating slash
+        else:
+                raise ValueError('sim:// url required')
+        f = open(filename, 'r');
+        state = 'header'
+        wroterev = False
+        while(True):
+                l = f.readline()
+                if l == '': break
+                if state == 'header' and l.startswith('Revision-number: '):
+                        state = 'prefix'
+                if state == 'prefix' and l == 'Revision-number: %s\n' % lower:
+                        state = 'selection'
+                if not upper == 'HEAD' and state == 'selection' and l == 'Revision-number: %s\n' % upper:
+                        break;
+
+                if state == 'header' or state == 'selection':
+                        if state == 'selection': wroterev = True
+                        sys.stdout.write(l)
+        return wroterev
+
+if __name__ == "__main__":
+        if not (len(sys.argv) in (3, 4, 5)):
+                print "usage: %s dump URL -rLOWER:UPPER"
+                sys.exit(1)
+        if not sys.argv[1] == 'dump': raise NotImplementedError('only "dump" is suppported.')
+        url = sys.argv[2]
+        r = ('0', 'HEAD')
+        if len(sys.argv) == 4 and sys.argv[3][0:2] == '-r':
+                r = sys.argv[3][2:].lstrip().split(':')
+        if not getrevlimit() is None: r[1] = getrevlimit()
+        if writedump(url, r[0], r[1]): ret = 0
+        else: ret = 1
+        sys.exit(ret)
diff --git a/remote-testsvn.c b/remote-testsvn.c
new file mode 100644
index 000000000..51fba059a
--- /dev/null
+++ b/remote-testsvn.c
@@ -0,0 +1,342 @@
+#include "cache.h"
+#include "remote.h"
+#include "strbuf.h"
+#include "url.h"
+#include "exec_cmd.h"
+#include "run-command.h"
+#include "vcs-svn/svndump.h"
+#include "notes.h"
+#include "argv-array.h"
+
+static const char *url;
+static int dump_from_file;
+static const char *private_ref;
+static const char *remote_ref = "refs/heads/master";
+static const char *marksfilename, *notes_ref;
+struct rev_note { unsigned int rev_nr; };
+
+static int cmd_capabilities(const char *line);
+static int cmd_import(const char *line);
+static int cmd_list(const char *line);
+
+typedef int (*input_command_handler)(const char *);
+struct input_command_entry {
+	const char *name;
+	input_command_handler fn;
+	unsigned char batchable;	/* whether the command starts or is part of a batch */
+};
+
+static const struct input_command_entry input_command_list[] = {
+	{ "capabilities", cmd_capabilities, 0 },
+	{ "import", cmd_import, 1 },
+	{ "list", cmd_list, 0 },
+	{ NULL, NULL }
+};
+
+static int cmd_capabilities(const char *line)
+{
+	printf("import\n");
+	printf("bidi-import\n");
+	printf("refspec %s:%s\n\n", remote_ref, private_ref);
+	fflush(stdout);
+	return 0;
+}
+
+static void terminate_batch(void)
+{
+	/* terminate a current batch's fast-import stream */
+	printf("done\n");
+	fflush(stdout);
+}
+
+/* NOTE: 'ref' refers to a git reference, while 'rev' refers to a svn revision. */
+static char *read_ref_note(const unsigned char sha1[20])
+{
+	const unsigned char *note_sha1;
+	char *msg = NULL;
+	unsigned long msglen;
+	enum object_type type;
+
+	init_notes(NULL, notes_ref, NULL, 0);
+	if (!(note_sha1 = get_note(NULL, sha1)))
+		return NULL;	/* note tree not found */
+	if (!(msg = read_sha1_file(note_sha1, &type, &msglen)))
+		error("Empty notes tree. %s", notes_ref);
+	else if (!msglen || type != OBJ_BLOB) {
+		error("Note contains unusable content. "
+			"Is something else using this notes tree? %s", notes_ref);
+		free(msg);
+		msg = NULL;
+	}
+	free_notes(NULL);
+	return msg;
+}
+
+static int parse_rev_note(const char *msg, struct rev_note *res)
+{
+	const char *key, *value, *end;
+	size_t len;
+
+	while (*msg) {
+		end = strchr(msg, '\n');
+		len = end ? end - msg : strlen(msg);
+
+		key = "Revision-number: ";
+		if (!prefixcmp(msg, key)) {
+			long i;
+			char *end;
+			value = msg + strlen(key);
+			i = strtol(value, &end, 0);
+			if (end == value || i < 0 || i > UINT32_MAX)
+				return -1;
+			res->rev_nr = i;
+		}
+		msg += len + 1;
+	}
+	return 0;
+}
+
+static int note2mark_cb(const unsigned char *object_sha1,
+		const unsigned char *note_sha1, char *note_path,
+		void *cb_data)
+{
+	FILE *file = (FILE *)cb_data;
+	char *msg;
+	unsigned long msglen;
+	enum object_type type;
+	struct rev_note note;
+
+	if (!(msg = read_sha1_file(note_sha1, &type, &msglen)) ||
+			!msglen || type != OBJ_BLOB) {
+		free(msg);
+		return 1;
+	}
+	if (parse_rev_note(msg, &note))
+		return 2;
+	if (fprintf(file, ":%d %s\n", note.rev_nr, sha1_to_hex(object_sha1)) < 1)
+		return 3;
+	return 0;
+}
+
+static void regenerate_marks(void)
+{
+	int ret;
+	FILE *marksfile = fopen(marksfilename, "w+");
+
+	if (!marksfile)
+		die_errno("Couldn't create mark file %s.", marksfilename);
+	ret = for_each_note(NULL, 0, note2mark_cb, marksfile);
+	if (ret)
+		die("Regeneration of marks failed, returned %d.", ret);
+	fclose(marksfile);
+}
+
+static void check_or_regenerate_marks(int latestrev)
+{
+	FILE *marksfile;
+	struct strbuf sb = STRBUF_INIT;
+	struct strbuf line = STRBUF_INIT;
+	int found = 0;
+
+	if (latestrev < 1)
+		return;
+
+	init_notes(NULL, notes_ref, NULL, 0);
+	marksfile = fopen(marksfilename, "r");
+	if (!marksfile) {
+		regenerate_marks();
+		marksfile = fopen(marksfilename, "r");
+		if (!marksfile)
+			die_errno("cannot read marks file %s!", marksfilename);
+		fclose(marksfile);
+	} else {
+		strbuf_addf(&sb, ":%d ", latestrev);
+		while (strbuf_getline(&line, marksfile, '\n') != EOF) {
+			if (!prefixcmp(line.buf, sb.buf)) {
+				found++;
+				break;
+			}
+		}
+		fclose(marksfile);
+		if (!found)
+			regenerate_marks();
+	}
+	free_notes(NULL);
+	strbuf_release(&sb);
+	strbuf_release(&line);
+}
+
+static int cmd_import(const char *line)
+{
+	int code;
+	int dumpin_fd;
+	char *note_msg;
+	unsigned char head_sha1[20];
+	unsigned int startrev;
+	struct argv_array svndump_argv = ARGV_ARRAY_INIT;
+	struct child_process svndump_proc;
+
+	if (read_ref(private_ref, head_sha1))
+		startrev = 0;
+	else {
+		note_msg = read_ref_note(head_sha1);
+		if(note_msg == NULL) {
+			warning("No note found for %s.", private_ref);
+			startrev = 0;
+		} else {
+			struct rev_note note = { 0 };
+			if (parse_rev_note(note_msg, &note))
+				die("Revision number couldn't be parsed from note.");
+			startrev = note.rev_nr + 1;
+			free(note_msg);
+		}
+	}
+	check_or_regenerate_marks(startrev - 1);
+
+	if (dump_from_file) {
+		dumpin_fd = open(url, O_RDONLY);
+		if(dumpin_fd < 0)
+			die_errno("Couldn't open svn dump file %s.", url);
+	} else {
+		memset(&svndump_proc, 0, sizeof(struct child_process));
+		svndump_proc.out = -1;
+		argv_array_push(&svndump_argv, "svnrdump");
+		argv_array_push(&svndump_argv, "dump");
+		argv_array_push(&svndump_argv, url);
+		argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev);
+		svndump_proc.argv = svndump_argv.argv;
+
+		code = start_command(&svndump_proc);
+		if (code)
+			die("Unable to start %s, code %d", svndump_proc.argv[0], code);
+		dumpin_fd = svndump_proc.out;
+	}
+	/* setup marks file import/export */
+	printf("feature import-marks-if-exists=%s\n"
+			"feature export-marks=%s\n", marksfilename, marksfilename);
+
+	svndump_init_fd(dumpin_fd, STDIN_FILENO);
+	svndump_read(url, private_ref, notes_ref);
+	svndump_deinit();
+	svndump_reset();
+
+	close(dumpin_fd);
+	if (!dump_from_file) {
+		code = finish_command(&svndump_proc);
+		if (code)
+			warning("%s, returned %d", svndump_proc.argv[0], code);
+		argv_array_clear(&svndump_argv);
+	}
+
+	return 0;
+}
+
+static int cmd_list(const char *line)
+{
+	printf("? %s\n\n", remote_ref);
+	fflush(stdout);
+	return 0;
+}
+
+static int do_command(struct strbuf *line)
+{
+	const struct input_command_entry *p = input_command_list;
+	static struct string_list batchlines = STRING_LIST_INIT_DUP;
+	static const struct input_command_entry *batch_cmd;
+	/*
+	 * commands can be grouped together in a batch.
+	 * Batches are ended by \n. If no batch is active the program ends.
+	 * During a batch all lines are buffered and passed to the handler function
+	 * when the batch is terminated.
+	 */
+	if (line->len == 0) {
+		if (batch_cmd) {
+			struct string_list_item *item;
+			for_each_string_list_item(item, &batchlines)
+				batch_cmd->fn(item->string);
+			terminate_batch();
+			batch_cmd = NULL;
+			string_list_clear(&batchlines, 0);
+			return 0;	/* end of the batch, continue reading other commands. */
+		}
+		return 1;	/* end of command stream, quit */
+	}
+	if (batch_cmd) {
+		if (prefixcmp(batch_cmd->name, line->buf))
+			die("Active %s batch interrupted by %s", batch_cmd->name, line->buf);
+		/* buffer batch lines */
+		string_list_append(&batchlines, line->buf);
+		return 0;
+	}
+
+	for (p = input_command_list; p->name; p++) {
+		if (!prefixcmp(line->buf, p->name) && (strlen(p->name) == line->len ||
+				line->buf[strlen(p->name)] == ' ')) {
+			if (p->batchable) {
+				batch_cmd = p;
+				string_list_append(&batchlines, line->buf);
+				return 0;
+			}
+			return p->fn(line->buf);
+		}
+	}
+	die("Unknown command '%s'\n", line->buf);
+	return 0;
+}
+
+int main(int argc, const char **argv)
+{
+	struct strbuf buf = STRBUF_INIT, url_sb = STRBUF_INIT,
+			private_ref_sb = STRBUF_INIT, marksfilename_sb = STRBUF_INIT,
+			notes_ref_sb = STRBUF_INIT;
+	static struct remote *remote;
+	const char *url_in;
+
+	git_extract_argv0_path(argv[0]);
+	setup_git_directory();
+	if (argc < 2 || argc > 3) {
+		usage("git-remote-svn <remote-name> [<url>]");
+		return 1;
+	}
+
+	remote = remote_get(argv[1]);
+	url_in = (argc == 3) ? argv[2] : remote->url[0];
+
+	if (!prefixcmp(url_in, "file://")) {
+		dump_from_file = 1;
+		url = url_decode(url_in + sizeof("file://")-1);
+	} else {
+		dump_from_file = 0;
+		end_url_with_slash(&url_sb, url_in);
+		url = url_sb.buf;
+	}
+
+	strbuf_addf(&private_ref_sb, "refs/svn/%s/master", remote->name);
+	private_ref = private_ref_sb.buf;
+
+	strbuf_addf(&notes_ref_sb, "refs/notes/%s/revs", remote->name);
+	notes_ref = notes_ref_sb.buf;
+
+	strbuf_addf(&marksfilename_sb, "%s/info/fast-import/remote-svn/%s.marks",
+		get_git_dir(), remote->name);
+	marksfilename = marksfilename_sb.buf;
+
+	while (1) {
+		if (strbuf_getline(&buf, stdin, '\n') == EOF) {
+			if (ferror(stdin))
+				die("Error reading command stream");
+			else
+				die("Unexpected end of command stream");
+		}
+		if (do_command(&buf))
+			break;
+		strbuf_reset(&buf);
+	}
+
+	strbuf_release(&buf);
+	strbuf_release(&url_sb);
+	strbuf_release(&private_ref_sb);
+	strbuf_release(&notes_ref_sb);
+	strbuf_release(&marksfilename_sb);
+	return 0;
+}
diff --git a/t/t9020-remote-svn.sh b/t/t9020-remote-svn.sh
new file mode 100755
index 000000000..4f2dfe0e3
--- /dev/null
+++ b/t/t9020-remote-svn.sh
@@ -0,0 +1,84 @@
+#!/bin/sh
+
+test_description='tests remote-svn'
+
+. ./test-lib.sh
+
+MARKSPATH=.git/info/fast-import/remote-svn
+
+if ! test_have_prereq PYTHON
+then
+	skip_all='skipping remote-svn tests, python not available'
+	test_done
+fi
+
+# We override svnrdump by placing a symlink to the svnrdump-emulator in .
+export PATH="$HOME:$PATH"
+ln -sf $GIT_BUILD_DIR/contrib/svn-fe/svnrdump_sim.py "$HOME/svnrdump"
+
+init_git () {
+	rm -fr .git &&
+	git init &&
+	#git remote add svnsim testsvn::sim:///$TEST_DIRECTORY/t9020/example.svnrdump
+	# let's reuse an exisiting dump file!?
+	git remote add svnsim testsvn::sim://$TEST_DIRECTORY/t9154/svn.dump
+	git remote add svnfile testsvn::file://$TEST_DIRECTORY/t9154/svn.dump
+}
+
+if test -e "$GIT_BUILD_DIR/git-remote-testsvn"
+then
+	test_set_prereq REMOTE_SVN
+fi
+
+test_debug '
+	git --version
+	which git
+	which svnrdump
+'
+
+test_expect_success REMOTE_SVN 'simple fetch' '
+	init_git &&
+	git fetch svnsim &&
+	test_cmp .git/refs/svn/svnsim/master .git/refs/remotes/svnsim/master  &&
+	cp .git/refs/remotes/svnsim/master master.good
+'
+
+test_debug '
+	cat .git/refs/svn/svnsim/master
+	cat .git/refs/remotes/svnsim/master
+'
+
+test_expect_success REMOTE_SVN 'repeated fetch, nothing shall change' '
+	git fetch svnsim &&
+	test_cmp master.good .git/refs/remotes/svnsim/master
+'
+
+test_expect_success REMOTE_SVN 'fetch from a file:// url gives the same result' '
+	git fetch svnfile
+'
+
+test_expect_failure REMOTE_SVN 'the sha1 differ because the git-svn-id line in the commit msg contains the url' '
+	test_cmp .git/refs/remotes/svnfile/master .git/refs/remotes/svnsim/master
+'
+
+test_expect_success REMOTE_SVN 'mark-file regeneration' '
+	# filter out any other marks, that can not be regenerated. Only up to 3 digit revisions are allowed here
+	grep ":[0-9]\{1,3\} " $MARKSPATH/svnsim.marks > $MARKSPATH/svnsim.marks.old &&
+	rm $MARKSPATH/svnsim.marks &&
+	git fetch svnsim &&
+	test_cmp $MARKSPATH/svnsim.marks.old $MARKSPATH/svnsim.marks
+'
+
+test_expect_success REMOTE_SVN 'incremental imports must lead to the same head' '
+	export SVNRMAX=3 &&
+	init_git &&
+	git fetch svnsim &&
+	test_cmp .git/refs/svn/svnsim/master .git/refs/remotes/svnsim/master  &&
+	unset SVNRMAX &&
+	git fetch svnsim &&
+	test_cmp master.good .git/refs/remotes/svnsim/master
+'
+
+test_debug 'git branch -a'
+
+test_done
diff --git a/test-svn-fe.c b/test-svn-fe.c
index 83633a21e..0f2d9a4a3 100644
--- a/test-svn-fe.c
+++ b/test-svn-fe.c
@@ -40,7 +40,7 @@ int main(int argc, char *argv[])
 	if (argc == 2) {
 		if (svndump_init(argv[1]))
 			return 1;
-		svndump_read(NULL);
+		svndump_read(NULL, "refs/heads/master", "refs/notes/svn/revs");
 		svndump_deinit();
 		svndump_reset();
 		return 0;
diff --git a/transport-helper.c b/transport-helper.c
index cfe098849..4713b6930 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -10,6 +10,7 @@
 #include "string-list.h"
 #include "thread-utils.h"
 #include "sigchain.h"
+#include "argv-array.h"
 
 static int debug;
 
@@ -19,6 +20,7 @@ struct helper_data {
 	FILE *out;
 	unsigned fetch : 1,
 		import : 1,
+		bidi_import : 1,
 		export : 1,
 		option : 1,
 		push : 1,
@@ -101,6 +103,7 @@ static void do_take_over(struct transport *transport)
 static struct child_process *get_helper(struct transport *transport)
 {
 	struct helper_data *data = transport->data;
+	struct argv_array argv = ARGV_ARRAY_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process *helper;
 	const char **refspecs = NULL;
@@ -122,11 +125,10 @@ static struct child_process *get_helper(struct transport *transport)
 	helper->in = -1;
 	helper->out = -1;
 	helper->err = 0;
-	helper->argv = xcalloc(4, sizeof(*helper->argv));
-	strbuf_addf(&buf, "git-remote-%s", data->name);
-	helper->argv[0] = strbuf_detach(&buf, NULL);
-	helper->argv[1] = transport->remote->name;
-	helper->argv[2] = remove_ext_force(transport->url);
+	argv_array_pushf(&argv, "git-remote-%s", data->name);
+	argv_array_push(&argv, transport->remote->name);
+	argv_array_push(&argv, remove_ext_force(transport->url));
+	helper->argv = argv_array_detach(&argv, NULL);
 	helper->git_cmd = 0;
 	helper->silent_exec_failure = 1;
 
@@ -178,6 +180,8 @@ static struct child_process *get_helper(struct transport *transport)
 			data->push = 1;
 		else if (!strcmp(capname, "import"))
 			data->import = 1;
+		else if (!strcmp(capname, "bidi-import"))
+			data->bidi_import = 1;
 		else if (!strcmp(capname, "export"))
 			data->export = 1;
 		else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
@@ -241,8 +245,7 @@ static int disconnect_helper(struct transport *transport)
 		close(data->helper->out);
 		fclose(data->out);
 		res = finish_command(data->helper);
-		free((char *)data->helper->argv[0]);
-		free(data->helper->argv);
+		argv_array_free_detached(data->helper->argv);
 		free(data->helper);
 		data->helper = NULL;
 	}
@@ -376,14 +379,23 @@ static int fetch_with_fetch(struct transport *transport,
 static int get_importer(struct transport *transport, struct child_process *fastimport)
 {
 	struct child_process *helper = get_helper(transport);
+	struct helper_data *data = transport->data;
+	struct argv_array argv = ARGV_ARRAY_INIT;
+	int cat_blob_fd, code;
 	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";
+	argv_array_push(&argv, "fast-import");
+	argv_array_push(&argv, debug ? "--stats" : "--quiet");
 
+	if (data->bidi_import) {
+		cat_blob_fd = xdup(helper->in);
+		argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
+	}
+	fastimport->argv = argv.argv;
 	fastimport->git_cmd = 1;
-	return start_command(fastimport);
+
+	code = start_command(fastimport);
+	return code;
 }
 
 static int get_exporter(struct transport *transport,
@@ -438,11 +450,17 @@ static int fetch_with_import(struct transport *transport,
 	}
 
 	write_constant(data->helper->in, "\n");
+	/*
+	 * remote-helpers that advertise the bidi-import capability are required to
+	 * buffer the complete batch of import commands until this newline before
+	 * sending data to fast-import.
+	 * These helpers read back data from fast-import on their stdin, which could
+	 * be mixed with import commands, otherwise.
+	 */
 
 	if (finish_command(&fastimport))
 		die("Error while running fast-import");
-	free(fastimport.argv);
-	fastimport.argv = NULL;
+	argv_array_free_detached(fastimport.argv);
 
 	/*
 	 * The fast-import stream of a remote helper that advertises
diff --git a/vcs-svn/fast_export.c b/vcs-svn/fast_export.c
index 1f0469786..f2b23c81d 100644
--- a/vcs-svn/fast_export.c
+++ b/vcs-svn/fast_export.c
@@ -3,8 +3,7 @@
  * See LICENSE for details.
  */
 
-#include "git-compat-util.h"
-#include "strbuf.h"
+#include "cache.h"
 #include "quote.h"
 #include "fast_export.h"
 #include "repo_tree.h"
@@ -68,11 +67,33 @@ void fast_export_modify(const char *path, uint32_t mode, const char *dataref)
 	putchar('\n');
 }
 
+void fast_export_begin_note(uint32_t revision, const char *author,
+		const char *log, unsigned long timestamp, const char *note_ref)
+{
+	static int firstnote = 1;
+	size_t loglen = strlen(log);
+	printf("commit %s\n", note_ref);
+	printf("committer %s <%s@%s> %ld +0000\n", author, author, "local", timestamp);
+	printf("data %"PRIuMAX"\n", (uintmax_t)loglen);
+	fwrite(log, loglen, 1, stdout);
+	if (firstnote) {
+		if (revision > 1)
+			printf("from %s^0", note_ref);
+		firstnote = 0;
+	}
+	fputc('\n', stdout);
+}
+
+void fast_export_note(const char *committish, const char *dataref)
+{
+	printf("N %s %s\n", dataref, committish);
+}
+
 static char gitsvnline[MAX_GITSVN_LINE_LEN];
 void fast_export_begin_commit(uint32_t revision, const char *author,
 			const struct strbuf *log,
 			const char *uuid, const char *url,
-			unsigned long timestamp)
+			unsigned long timestamp, const char *local_ref)
 {
 	static const struct strbuf empty = STRBUF_INIT;
 	if (!log)
@@ -84,7 +105,7 @@ void fast_export_begin_commit(uint32_t revision, const char *author,
 	} else {
 		*gitsvnline = '\0';
 	}
-	printf("commit refs/heads/master\n");
+	printf("commit %s\n", local_ref);
 	printf("mark :%"PRIu32"\n", revision);
 	printf("committer %s <%s@%s> %ld +0000\n",
 		   *author ? author : "nobody",
@@ -222,6 +243,13 @@ static long apply_delta(off_t len, struct line_buffer *input,
 	return ret;
 }
 
+void fast_export_buf_to_data(const struct strbuf *data)
+{
+	printf("data %"PRIuMAX"\n", (uintmax_t)data->len);
+	fwrite(data->buf, data->len, 1, stdout);
+	fputc('\n', stdout);
+}
+
 void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input)
 {
 	assert(len >= 0);
diff --git a/vcs-svn/fast_export.h b/vcs-svn/fast_export.h
index 8823aca15..c8b5adb81 100644
--- a/vcs-svn/fast_export.h
+++ b/vcs-svn/fast_export.h
@@ -9,11 +9,15 @@ void fast_export_deinit(void);
 
 void fast_export_delete(const char *path);
 void fast_export_modify(const char *path, uint32_t mode, const char *dataref);
+void fast_export_note(const char *committish, const char *dataref);
+void fast_export_begin_note(uint32_t revision, const char *author,
+		const char *log, unsigned long timestamp, const char *note_ref);
 void fast_export_begin_commit(uint32_t revision, const char *author,
-			const struct strbuf *log, const char *uuid,
-			const char *url, unsigned long timestamp);
+			const struct strbuf *log, const char *uuid,const char *url,
+			unsigned long timestamp, const char *local_ref);
 void fast_export_end_commit(uint32_t revision);
 void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input);
+void fast_export_buf_to_data(const struct strbuf *data);
 void fast_export_blob_delta(uint32_t mode,
 			uint32_t old_mode, const char *old_data,
 			off_t len, struct line_buffer *input);
diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c
index 2b168aee7..31d1d83d4 100644
--- a/vcs-svn/svndump.c
+++ b/vcs-svn/svndump.c
@@ -48,7 +48,7 @@ static struct {
 static struct {
 	uint32_t revision;
 	unsigned long timestamp;
-	struct strbuf log, author;
+	struct strbuf log, author, note;
 } rev_ctx;
 
 static struct {
@@ -77,6 +77,7 @@ static void reset_rev_ctx(uint32_t revision)
 	rev_ctx.timestamp = 0;
 	strbuf_reset(&rev_ctx.log);
 	strbuf_reset(&rev_ctx.author);
+	strbuf_reset(&rev_ctx.note);
 }
 
 static void reset_dump_ctx(const char *url)
@@ -299,22 +300,29 @@ static void handle_node(void)
 				node_ctx.text_length, &input);
 }
 
-static void begin_revision(void)
+static void begin_revision(const char *remote_ref)
 {
 	if (!rev_ctx.revision)	/* revision 0 gets no git commit. */
 		return;
 	fast_export_begin_commit(rev_ctx.revision, rev_ctx.author.buf,
 		&rev_ctx.log, dump_ctx.uuid.buf, dump_ctx.url.buf,
-		rev_ctx.timestamp);
+		rev_ctx.timestamp, remote_ref);
 }
 
-static void end_revision(void)
+static void end_revision(const char *note_ref)
 {
-	if (rev_ctx.revision)
+	struct strbuf mark = STRBUF_INIT;
+	if (rev_ctx.revision) {
 		fast_export_end_commit(rev_ctx.revision);
+		fast_export_begin_note(rev_ctx.revision, "remote-svn",
+				"Note created by remote-svn.", rev_ctx.timestamp, note_ref);
+		strbuf_addf(&mark, ":%"PRIu32, rev_ctx.revision);
+		fast_export_note(mark.buf, "inline");
+		fast_export_buf_to_data(&rev_ctx.note);
+	}
 }
 
-void svndump_read(const char *url)
+void svndump_read(const char *url, const char *local_ref, const char *notes_ref)
 {
 	char *val;
 	char *t;
@@ -353,11 +361,12 @@ void svndump_read(const char *url)
 			if (active_ctx == NODE_CTX)
 				handle_node();
 			if (active_ctx == REV_CTX)
-				begin_revision();
+				begin_revision(local_ref);
 			if (active_ctx != DUMP_CTX)
-				end_revision();
+				end_revision(notes_ref);
 			active_ctx = REV_CTX;
 			reset_rev_ctx(atoi(val));
+			strbuf_addf(&rev_ctx.note, "%s\n", t);
 			break;
 		case sizeof("Node-path"):
 			if (constcmp(t, "Node-"))
@@ -366,13 +375,15 @@ void svndump_read(const char *url)
 				if (active_ctx == NODE_CTX)
 					handle_node();
 				if (active_ctx == REV_CTX)
-					begin_revision();
+					begin_revision(local_ref);
 				active_ctx = NODE_CTX;
 				reset_node_ctx(val);
+				strbuf_addf(&rev_ctx.note, "%s\n", t);
 				break;
 			}
 			if (constcmp(t + strlen("Node-"), "kind"))
 				continue;
+			strbuf_addf(&rev_ctx.note, "%s\n", t);
 			if (!strcmp(val, "dir"))
 				node_ctx.type = REPO_MODE_DIR;
 			else if (!strcmp(val, "file"))
@@ -383,6 +394,7 @@ void svndump_read(const char *url)
 		case sizeof("Node-action"):
 			if (constcmp(t, "Node-action"))
 				continue;
+			strbuf_addf(&rev_ctx.note, "%s\n", t);
 			if (!strcmp(val, "delete")) {
 				node_ctx.action = NODEACT_DELETE;
 			} else if (!strcmp(val, "add")) {
@@ -401,11 +413,13 @@ void svndump_read(const char *url)
 				continue;
 			strbuf_reset(&node_ctx.src);
 			strbuf_addstr(&node_ctx.src, val);
+			strbuf_addf(&rev_ctx.note, "%s\n", t);
 			break;
 		case sizeof("Node-copyfrom-rev"):
 			if (constcmp(t, "Node-copyfrom-rev"))
 				continue;
 			node_ctx.srcRev = atoi(val);
+			strbuf_addf(&rev_ctx.note, "%s\n", t);
 			break;
 		case sizeof("Text-content-length"):
 			if (constcmp(t, "Text") && constcmp(t, "Prop"))
@@ -463,25 +477,40 @@ void svndump_read(const char *url)
 	if (active_ctx == NODE_CTX)
 		handle_node();
 	if (active_ctx == REV_CTX)
-		begin_revision();
+		begin_revision(local_ref);
 	if (active_ctx != DUMP_CTX)
-		end_revision();
+		end_revision(notes_ref);
 }
 
-int svndump_init(const char *filename)
+static void init(int report_fd)
 {
-	if (buffer_init(&input, filename))
-		return error("cannot open %s: %s", filename, strerror(errno));
-	fast_export_init(REPORT_FILENO);
+	fast_export_init(report_fd);
 	strbuf_init(&dump_ctx.uuid, 4096);
 	strbuf_init(&dump_ctx.url, 4096);
 	strbuf_init(&rev_ctx.log, 4096);
 	strbuf_init(&rev_ctx.author, 4096);
+	strbuf_init(&rev_ctx.note, 4096);
 	strbuf_init(&node_ctx.src, 4096);
 	strbuf_init(&node_ctx.dst, 4096);
 	reset_dump_ctx(NULL);
 	reset_rev_ctx(0);
 	reset_node_ctx(NULL);
+	return;
+}
+
+int svndump_init(const char *filename)
+{
+	if (buffer_init(&input, filename))
+		return error("cannot open %s: %s", filename ? filename : "NULL", strerror(errno));
+	init(REPORT_FILENO);
+	return 0;
+}
+
+int svndump_init_fd(int in_fd, int back_fd)
+{
+	if(buffer_fdinit(&input, xdup(in_fd)))
+		return error("cannot open fd %d: %s", in_fd, strerror(errno));
+	init(xdup(back_fd));
 	return 0;
 }
 
@@ -492,6 +521,8 @@ void svndump_deinit(void)
 	reset_rev_ctx(0);
 	reset_node_ctx(NULL);
 	strbuf_release(&rev_ctx.log);
+	strbuf_release(&rev_ctx.author);
+	strbuf_release(&rev_ctx.note);
 	strbuf_release(&node_ctx.src);
 	strbuf_release(&node_ctx.dst);
 	if (buffer_deinit(&input))
diff --git a/vcs-svn/svndump.h b/vcs-svn/svndump.h
index df9ceb0e8..b8eb12954 100644
--- a/vcs-svn/svndump.h
+++ b/vcs-svn/svndump.h
@@ -2,7 +2,8 @@
 #define SVNDUMP_H_
 
 int svndump_init(const char *filename);
-void svndump_read(const char *url);
+int svndump_init_fd(int in_fd, int back_fd);
+void svndump_read(const char *url, const char *local_ref, const char *notes_ref);
 void svndump_deinit(void);
 void svndump_reset(void);