[PATCH v3 00/12] Reroll of the remote-vcs-helper series

[PATCH v3 00/12] Reroll of the remote-vcs-helper series

[Sverre Rabbelier]

My helper is fully functional now so I think after one more round
this will be ready for next (we need some more documentation).

Daniel Barkalow (8):
      Fix memory leak in helper method for disconnect
      Allow programs to not depend on remotes having urls
      Use a function to determine whether a remote is valid
      Allow fetch to modify refs
      Add a config option for remotes to specify a foreign vcs
      Add support for "import" helper command
      Allow helper to map private ref names into normal names
      Allow helpers to report in "list" command that the ref is unchanged

Johan Herland (1):
      Basic build infrastructure for Python scripts

Johannes Schindelin (1):
      Allow specifying the remote helper in the url

Sverre Rabbelier (2):
      Allow helpers to request the path to the .git directory
      Add Python support library for remote helpers

 Documentation/config.txt             |    4 +
 Documentation/git-remote-helpers.txt |   14 +-
 Makefile                             |   51 +++
 builtin-clone.c                      |    3 +-
 builtin-fetch.c                      |    7 +-
 builtin-ls-remote.c                  |    4 +-
 builtin-push.c                       |   68 ++--
 configure.ac                         |    3 +
 git_remote_helpers/.gitignore        |    2 +
 git_remote_helpers/Makefile          |   35 ++
 git_remote_helpers/__init__.py       |   16 +
 git_remote_helpers/git/git.py        |  678 ++++++++++++++++++++++++++++++++++
 git_remote_helpers/setup.py          |   17 +
 git_remote_helpers/util.py           |  194 ++++++++++
 remote.c                             |   32 ++-
 remote.h                             |    5 +
 t/test-lib.sh                        |   10 +
 transport-helper.c                   |  117 ++++++-
 transport.c                          |   31 ++-
 transport.h                          |   41 ++-
 20 files changed, 1285 insertions(+), 47 deletions(-)

[PATCH v3 01/12] Fix memory leak in helper method for disconnect

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

Since some cases may need to disconnect from the helper and reconnect,
wrap the function that just disconnects in a function that also frees
transport->data.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
---

	Unchanged.

 transport-helper.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/transport-helper.c b/transport-helper.c
index f57e84c..e24fcbb 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -67,6 +67,13 @@ static int disconnect_helper(struct transport *transport)
 	return 0;
 }
 
+static int release_helper(struct transport *transport)
+{
+	disconnect_helper(transport);
+	free(transport->data);
+	return 0;
+}
+
 static int fetch_with_fetch(struct transport *transport,
 			    int nr_heads, const struct ref **to_fetch)
 {
@@ -163,6 +170,6 @@ int transport_helper_init(struct transport *transport, const char *name)
 	transport->data = data;
 	transport->get_refs_list = get_refs_list;
 	transport->fetch = fetch;
-	transport->disconnect = disconnect_helper;
+	transport->disconnect = release_helper;
 	return 0;
 }
-- 
1.6.5.2.158.g6dacb

[PATCH v3 02/12] Allow programs to not depend on remotes having urls

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

For fetch and ls-remote, which use the first url of a remote, have
transport_get() determine this by passing a remote and passing NULL
for the url. For push, which uses every url of a remote, use each url
in turn if there are any, and use NULL if there are none.

This will allow the transport code to do something different if the
location is not specified with a url.

Also, have the message for a fetch say "foreign" if there is no url.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Unchanged.

 builtin-fetch.c     |    7 +++-
 builtin-ls-remote.c |    4 +-
 builtin-push.c      |   68 +++++++++++++++++++++++++++++++-------------------
 transport.c         |    3 ++
 4 files changed, 52 insertions(+), 30 deletions(-)

diff --git a/builtin-fetch.c b/builtin-fetch.c
index a35a6f8..013a6ba 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -309,7 +309,10 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 	if (!fp)
 		return error("cannot open %s: %s\n", filename, strerror(errno));
 
-	url = transport_anonymize_url(raw_url);
+	if (raw_url)
+		url = transport_anonymize_url(raw_url);
+	else
+		url = xstrdup("foreign");
 	for (rm = ref_map; rm; rm = rm->next) {
 		struct ref *ref = NULL;
 
@@ -704,7 +707,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	if (!remote)
 		die("Where do you want to fetch from today?");
 
-	transport = transport_get(remote, remote->url[0]);
+	transport = transport_get(remote, NULL);
 	if (verbosity >= 2)
 		transport->verbose = 1;
 	if (verbosity < 0)
diff --git a/builtin-ls-remote.c b/builtin-ls-remote.c
index 78a88f7..4c6fc58 100644
--- a/builtin-ls-remote.c
+++ b/builtin-ls-remote.c
@@ -87,9 +87,9 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 		}
 	}
 	remote = nongit ? NULL : remote_get(dest);
-	if (remote && !remote->url_nr)
+	if (!nongit && !remote)
 		die("remote %s has no configured URL", dest);
-	transport = transport_get(remote, remote ? remote->url[0] : dest);
+	transport = transport_get(remote, remote ? NULL : dest);
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
diff --git a/builtin-push.c b/builtin-push.c
index 8631c06..88dd9f5 100644
--- a/builtin-push.c
+++ b/builtin-push.c
@@ -88,6 +88,36 @@ static void setup_default_push_refspecs(void)
 	}
 }
 
+static int push_with_options(struct transport *transport, int flags)
+{
+	int err;
+	int nonfastforward;
+	if (receivepack)
+		transport_set_option(transport,
+				     TRANS_OPT_RECEIVEPACK, receivepack);
+	if (thin)
+		transport_set_option(transport, TRANS_OPT_THIN, "yes");
+
+	if (flags & TRANSPORT_PUSH_VERBOSE)
+		fprintf(stderr, "Pushing to %s\n", transport->url);
+	err = transport_push(transport, refspec_nr, refspec, flags,
+			     &nonfastforward);
+	err |= transport_disconnect(transport);
+
+	if (!err)
+		return 0;
+
+	error("failed to push some refs to '%s'", transport->url);
+
+	if (nonfastforward && advice_push_nonfastforward) {
+		printf("To prevent you from losing history, non-fast-forward updates were rejected\n"
+		       "Merge the remote changes before pushing again.  See the 'non-fast forward'\n"
+		       "section of 'git push --help' for details.\n");
+	}
+
+	return 1;
+}
+
 static int do_push(const char *repo, int flags)
 {
 	int i, errs;
@@ -136,33 +166,19 @@ static int do_push(const char *repo, int flags)
 		url = remote->url;
 		url_nr = remote->url_nr;
 	}
-	for (i = 0; i < url_nr; i++) {
-		struct transport *transport =
-			transport_get(remote, url[i]);
-		int err;
-		int nonfastforward;
-		if (receivepack)
-			transport_set_option(transport,
-					     TRANS_OPT_RECEIVEPACK, receivepack);
-		if (thin)
-			transport_set_option(transport, TRANS_OPT_THIN, "yes");
-
-		if (flags & TRANSPORT_PUSH_VERBOSE)
-			fprintf(stderr, "Pushing to %s\n", url[i]);
-		err = transport_push(transport, refspec_nr, refspec, flags,
-				     &nonfastforward);
-		err |= transport_disconnect(transport);
-
-		if (!err)
-			continue;
-
-		error("failed to push some refs to '%s'", url[i]);
-		if (nonfastforward && advice_push_nonfastforward) {
-			printf("To prevent you from losing history, non-fast-forward updates were rejected\n"
-			       "Merge the remote changes before pushing again.  See the 'non-fast forward'\n"
-			       "section of 'git push --help' for details.\n");
+	if (url_nr) {
+		for (i = 0; i < url_nr; i++) {
+			struct transport *transport =
+				transport_get(remote, url[i]);
+			if (push_with_options(transport, flags))
+				errs++;
 		}
-		errs++;
+	} else {
+		struct transport *transport =
+			transport_get(remote, NULL);
+
+		if (push_with_options(transport, flags))
+			errs++;
 	}
 	return !!errs;
 }
diff --git a/transport.c b/transport.c
index 644a30a..9daa686 100644
--- a/transport.c
+++ b/transport.c
@@ -813,6 +813,9 @@ struct transport *transport_get(struct remote *remote, const char *url)
 	struct transport *ret = xcalloc(1, sizeof(*ret));
 
 	ret->remote = remote;
+
+	if (!url && remote && remote->url)
+		url = remote->url[0];
 	ret->url = url;
 
 	if (!prefixcmp(url, "rsync:")) {
-- 
1.6.5.2.158.g6dacb

[PATCH v3 03/12] Use a function to determine whether a remote is valid

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

Currently, it only checks url, but it will allow other things in the future.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
---

	Unchanged.

 remote.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/remote.c b/remote.c
index 73d33f2..15c9cec 100644
--- a/remote.c
+++ b/remote.c
@@ -52,6 +52,11 @@ static struct rewrites rewrites_push;
 #define BUF_SIZE (2048)
 static char buffer[BUF_SIZE];
 
+static int valid_remote(const struct remote *remote)
+{
+	return !!remote->url;
+}
+
 static const char *alias_url(const char *url, struct rewrites *r)
 {
 	int i, j;
@@ -688,14 +693,14 @@ struct remote *remote_get(const char *name)
 
 	ret = make_remote(name, 0);
 	if (valid_remote_nick(name)) {
-		if (!ret->url)
+		if (!valid_remote(ret))
 			read_remotes_file(ret);
-		if (!ret->url)
+		if (!valid_remote(ret))
 			read_branches_file(ret);
 	}
-	if (name_given && !ret->url)
+	if (name_given && !valid_remote(ret))
 		add_url_alias(ret, name);
-	if (!ret->url)
+	if (!valid_remote(ret))
 		return NULL;
 	ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
 	ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
-- 
1.6.5.2.158.g6dacb

[PATCH v3 04/12] Allow fetch to modify refs

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

This allows the transport to use the null sha1 for a ref reported to
be present in the remote repository to indicate that a ref exists but
its actual value is presently unknown and will be set if the objects
are fetched.

Also adds documentation to the API to specify exactly what the methods
should do and how they should interpret arguments.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Unchanged.

 builtin-clone.c    |    3 ++-
 transport-helper.c |    4 ++--
 transport.c        |   13 +++++++------
 transport.h        |   41 +++++++++++++++++++++++++++++++++++++++--
 4 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/builtin-clone.c b/builtin-clone.c
index caf3025..5df8b0f 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c
@@ -362,9 +362,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	const char *repo_name, *repo, *work_tree, *git_dir;
 	char *path, *dir;
 	int dest_exists;
-	const struct ref *refs, *remote_head, *mapped_refs;
+	const struct ref *refs, *remote_head;
 	const struct ref *remote_head_points_at;
 	const struct ref *our_head_points_at;
+	struct ref *mapped_refs;
 	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
diff --git a/transport-helper.c b/transport-helper.c
index e24fcbb..53d8f08 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -75,7 +75,7 @@ static int release_helper(struct transport *transport)
 }
 
 static int fetch_with_fetch(struct transport *transport,
-			    int nr_heads, const struct ref **to_fetch)
+			    int nr_heads, struct ref **to_fetch)
 {
 	struct child_process *helper = get_helper(transport);
 	FILE *file = xfdopen(helper->out, "r");
@@ -99,7 +99,7 @@ static int fetch_with_fetch(struct transport *transport,
 }
 
 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;
diff --git a/transport.c b/transport.c
index 9daa686..5ae8db6 100644
--- a/transport.c
+++ b/transport.c
@@ -204,7 +204,7 @@ static struct ref *get_refs_via_rsync(struct transport *transport, int for_push)
 }
 
 static int fetch_objs_via_rsync(struct transport *transport,
-				int nr_objs, const struct ref **to_fetch)
+				int nr_objs, struct ref **to_fetch)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process rsync;
@@ -408,7 +408,7 @@ static struct ref *get_refs_from_bundle(struct transport *transport, int for_pus
 }
 
 static int fetch_refs_from_bundle(struct transport *transport,
-			       int nr_heads, const struct ref **to_fetch)
+			       int nr_heads, struct ref **to_fetch)
 {
 	struct bundle_transport_data *data = transport->data;
 	return unbundle(&data->header, data->fd);
@@ -486,7 +486,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 }
 
 static int fetch_refs_via_pack(struct transport *transport,
-			       int nr_heads, const struct ref **to_fetch)
+			       int nr_heads, struct ref **to_fetch)
 {
 	struct git_transport_data *data = transport->data;
 	char **heads = xmalloc(nr_heads * sizeof(*heads));
@@ -926,16 +926,17 @@ const struct ref *transport_get_remote_refs(struct transport *transport)
 	return transport->remote_refs;
 }
 
-int transport_fetch_refs(struct transport *transport, const struct ref *refs)
+int transport_fetch_refs(struct transport *transport, struct ref *refs)
 {
 	int rc;
 	int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
-	const struct ref **heads = NULL;
-	const struct ref *rm;
+	struct ref **heads = NULL;
+	struct ref *rm;
 
 	for (rm = refs; rm; rm = rm->next) {
 		nr_refs++;
 		if (rm->peer_ref &&
+		    !is_null_sha1(rm->old_sha1) &&
 		    !hashcmp(rm->peer_ref->old_sha1, rm->old_sha1))
 			continue;
 		ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
diff --git a/transport.h b/transport.h
index c14da6f..503db11 100644
--- a/transport.h
+++ b/transport.h
@@ -18,11 +18,48 @@ struct transport {
 	int (*set_option)(struct transport *connection, const char *name,
 			  const char *value);
 
+	/**
+	 * Returns a list of the remote side's refs. In order to allow
+	 * the transport to try to share connections, for_push is a
+	 * hint as to whether the ultimate operation is a push or a fetch.
+	 *
+	 * If the transport is able to determine the remote hash for
+	 * the ref without a huge amount of effort, it should store it
+	 * in the ref's old_sha1 field; otherwise it should be all 0.
+	 **/
 	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
-	int (*fetch)(struct transport *transport, int refs_nr, const struct ref **refs);
+
+	/**
+	 * Fetch the objects for the given refs. Note that this gets
+	 * an array, and should ignore the list structure.
+	 *
+	 * If the transport did not get hashes for refs in
+	 * get_refs_list(), it should set the old_sha1 fields in the
+	 * provided refs now.
+	 **/
+	int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
+
+	/**
+	 * Push the objects and refs. Send the necessary objects, and
+	 * then, for any refs where peer_ref is set and
+	 * peer_ref->new_sha1 is different from old_sha1, tell the
+	 * remote side to update each ref in the list from old_sha1 to
+	 * peer_ref->new_sha1.
+	 *
+	 * Where possible, set the status for each ref appropriately.
+	 *
+	 * The transport must modify new_sha1 in the ref to the new
+	 * value if the remote accepted the change. Note that this
+	 * could be a different value from peer_ref->new_sha1 if the
+	 * process involved generating new commits.
+	 **/
 	int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
 	int (*push)(struct transport *connection, int refspec_nr, const char **refspec, int flags);
 
+	/** get_refs_list(), fetch(), and push_refs() can keep
+	 * resources (such as a connection) reserved for futher
+	 * use. disconnect() releases these resources.
+	 **/
 	int (*disconnect)(struct transport *connection);
 	char *pack_lockfile;
 	signed verbose : 2;
@@ -74,7 +111,7 @@ int transport_push(struct transport *connection,
 
 const struct ref *transport_get_remote_refs(struct transport *transport);
 
-int transport_fetch_refs(struct transport *transport, const struct ref *refs);
+int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
 int transport_disconnect(struct transport *transport);
 char *transport_anonymize_url(const char *url);
-- 
1.6.5.2.158.g6dacb

[PATCH v3 05/12] Add a config option for remotes to specify a foreign vcs

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

If this is set, the url is not required, and the transport always uses
a helper named "git-remote-<value>".

It is a separate configuration option in order to allow a sensible
configuration for foreign systems which either have no meaningful urls
for repositories or which require urls that do not specify the system
used by the repository at that location. However, this only affects
how the name of the helper is determined, not anything about the
interaction with the helper, and the contruction is such that, if the
foreign scm does happen to use a co-named url method, a url with that
method may be used directly.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Unchanged.

 Documentation/config.txt |    4 ++++
 remote.c                 |    4 +++-
 remote.h                 |    2 ++
 transport.c              |    5 +++++
 4 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d1e2120..0d9d369 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1408,6 +1408,10 @@ remote.<name>.tagopt::
 	Setting this value to \--no-tags disables automatic tag following when
 	fetching from remote <name>
 
+remote.<name>.vcs::
+	Setting this to a value <vcs> will cause git to interact with
+	the remote with the git-remote-<vcs> helper.
+
 remotes.<group>::
 	The list of remotes which are fetched by "git remote update
 	<group>".  See linkgit:git-remote[1].
diff --git a/remote.c b/remote.c
index 15c9cec..09bb79c 100644
--- a/remote.c
+++ b/remote.c
@@ -54,7 +54,7 @@ static char buffer[BUF_SIZE];
 
 static int valid_remote(const struct remote *remote)
 {
-	return !!remote->url;
+	return (!!remote->url) || (!!remote->foreign_vcs);
 }
 
 static const char *alias_url(const char *url, struct rewrites *r)
@@ -444,6 +444,8 @@ static int handle_config(const char *key, const char *value, void *cb)
 	} else if (!strcmp(subkey, ".proxy")) {
 		return git_config_string((const char **)&remote->http_proxy,
 					 key, value);
+	} else if (!strcmp(subkey, ".vcs")) {
+		return git_config_string(&remote->foreign_vcs, key, value);
 	}
 	return 0;
 }
diff --git a/remote.h b/remote.h
index 5db8420..ac0ce2f 100644
--- a/remote.h
+++ b/remote.h
@@ -11,6 +11,8 @@ struct remote {
 	const char *name;
 	int origin;
 
+	const char *foreign_vcs;
+
 	const char **url;
 	int url_nr;
 	int url_alloc;
diff --git a/transport.c b/transport.c
index 5ae8db6..13bab4e 100644
--- a/transport.c
+++ b/transport.c
@@ -818,6 +818,11 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		url = remote->url[0];
 	ret->url = url;
 
+	if (remote && remote->foreign_vcs) {
+		transport_helper_init(ret, remote->foreign_vcs);
+		return ret;
+	}
+
 	if (!prefixcmp(url, "rsync:")) {
 		ret->get_refs_list = get_refs_via_rsync;
 		ret->fetch = fetch_objs_via_rsync;
-- 
1.6.5.2.158.g6dacb

[PATCH v3 06/12] Allow specifying the remote helper in the url

[Sverre Rabbelier]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

The common case for remote helpers will be to import some repository
which can be specified by a single URL.  Support this use case by
allowing users to say:

	git clone hg::https://soc.googlecode.com/hg/ soc

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Unchanged.

 transport.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/transport.c b/transport.c
index 13bab4e..5d814b5 100644
--- a/transport.c
+++ b/transport.c
@@ -818,6 +818,16 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		url = remote->url[0];
 	ret->url = url;
 
+	/* maybe it is a foreign URL? */
+	if (url) {
+		const char *p = url;
+
+		while (isalnum(*p))
+			p++;
+		if (!prefixcmp(p, "::"))
+			remote->foreign_vcs = xstrndup(url, p - url);
+	}
+
 	if (remote && remote->foreign_vcs) {
 		transport_helper_init(ret, remote->foreign_vcs);
 		return ret;
-- 
1.6.5.2.158.g6dacb

[PATCH v3 07/12] Add support for "import" helper command

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

This command, supported if the "import" capability is advertized,
allows a helper to support fetching by outputting a git-fast-import
stream.

If both "fetch" and "import" are advertized, git itself will use
"fetch" (although other users may use "import" in this case).

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Unchanged.

 Documentation/git-remote-helpers.txt |   10 ++++++
 transport-helper.c                   |   52 ++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index 173ee23..e9aa67e 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -43,6 +43,13 @@ Commands are given by the caller on the helper's standard input, one per line.
 +
 Supported if the helper has the "fetch" capability.
 
+'import' <name>::
+	Produces a fast-import stream which imports the current value
+	of the named ref. It may additionally import other refs as
+	needed to construct the history efficiently.
++
+Supported if the helper has the "import" capability.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without
@@ -57,6 +64,9 @@ CAPABILITIES
 'fetch'::
 	This helper supports the 'fetch' command.
 
+'import'::
+	This helper supports the 'import' command.
+
 REF LIST ATTRIBUTES
 -------------------
 
diff --git a/transport-helper.c b/transport-helper.c
index 53d8f08..82caaae 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -11,6 +11,7 @@ struct helper_data
 	const char *name;
 	struct child_process *helper;
 	unsigned fetch : 1;
+	unsigned import : 1;
 };
 
 static struct child_process *get_helper(struct transport *transport)
@@ -48,6 +49,8 @@ static struct child_process *get_helper(struct transport *transport)
 			break;
 		if (!strcmp(buf.buf, "fetch"))
 			data->fetch = 1;
+		if (!strcmp(buf.buf, "import"))
+			data->import = 1;
 	}
 	return data->helper;
 }
@@ -98,6 +101,52 @@ 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 child_process *helper = get_helper(transport);
+	int i;
+	struct ref *posn;
+	struct strbuf buf = STRBUF_INIT;
+
+	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);
+		write_in_full(helper->in, buf.buf, buf.len);
+		strbuf_reset(&buf);
+	}
+	disconnect_helper(transport);
+	finish_command(&fastimport);
+
+	for (i = 0; i < nr_heads; i++) {
+		posn = to_fetch[i];
+		if (posn->status & REF_STATUS_UPTODATE)
+			continue;
+		read_ref(posn->name, posn->old_sha1);
+	}
+	return 0;
+}
+
 static int fetch(struct transport *transport,
 		 int nr_heads, struct ref **to_fetch)
 {
@@ -115,6 +164,9 @@ 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;
 }
 
-- 
1.6.5.2.158.g6dacb

[PATCH v3 08/12] Allow helper to map private ref names into normal names

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

This allows a helper to say that, when it handles "import
refs/heads/topic", the script it outputs will actually write to
refs/svn/origin/branches/topic; therefore, transport-helper should
read it from the latter location after git-fast-import completes.
---

	New in this series.
	Daniel, you did not include a S-o-b, I assume because you
	mean to add documentation?

 remote.c           |   17 +++++++++++++++++
 remote.h           |    3 +++
 transport-helper.c |   26 +++++++++++++++++++++++++-
 3 files changed, 45 insertions(+), 1 deletions(-)

diff --git a/remote.c b/remote.c
index 09bb79c..09e14a8 100644
--- a/remote.c
+++ b/remote.c
@@ -811,6 +811,23 @@ static int match_name_with_pattern(const char *key, const char *name,
 	return ret;
 }
 
+char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
+		     const char *name)
+{
+	int i;
+	char *ret = NULL;
+	for (i = 0; i < nr_refspec; i++) {
+		struct refspec *refspec = refspecs + i;
+		if (refspec->pattern) {
+			if (match_name_with_pattern(refspec->src, name,
+						    refspec->dst, &ret))
+				return ret;
+		} else if (!strcmp(refspec->src, name))
+			return strdup(refspec->dst);
+	}
+	return NULL;
+}
+
 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 {
 	int find_src = refspec->src == NULL;
diff --git a/remote.h b/remote.h
index ac0ce2f..c2f920b 100644
--- a/remote.h
+++ b/remote.h
@@ -91,6 +91,9 @@ void ref_remove_duplicates(struct ref *ref_map);
 int valid_fetch_refspec(const char *refspec);
 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec);
 
+char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
+		     const char *name);
+
 int match_refs(struct ref *src, struct ref **dst,
 	       int nr_refspec, const char **refspec, int all);
 
diff --git a/transport-helper.c b/transport-helper.c
index 82caaae..c4ab84a 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -5,6 +5,7 @@
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
+#include "remote.h"
 
 struct helper_data
 {
@@ -12,6 +13,9 @@ struct helper_data
 	struct child_process *helper;
 	unsigned fetch : 1;
 	unsigned import : 1;
+	/* These go from remote name (as in "list") to private name */
+	struct refspec *refspecs;
+	int refspec_nr;
 };
 
 static struct child_process *get_helper(struct transport *transport)
@@ -20,6 +24,9 @@ static struct child_process *get_helper(struct transport *transport)
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process *helper;
 	FILE *file;
+	const char **refspecs = NULL;
+	int refspec_nr = 0;
+	int refspec_alloc = 0;
 
 	if (data->helper)
 		return data->helper;
@@ -51,6 +58,16 @@ static struct child_process *get_helper(struct transport *transport)
 			data->fetch = 1;
 		if (!strcmp(buf.buf, "import"))
 			data->import = 1;
+		if (!prefixcmp(buf.buf, "refspec ")) {
+			ALLOC_GROW(refspecs,
+				   refspec_nr + 1,
+				   refspec_alloc);
+			refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
+		}
+	}
+	if (refspecs) {
+		data->refspec_nr = refspec_nr;
+		data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 	}
 	return data->helper;
 }
@@ -119,6 +136,7 @@ static int fetch_with_import(struct transport *transport,
 {
 	struct child_process fastimport;
 	struct child_process *helper = get_helper(transport);
+	struct helper_data *data = transport->data;
 	int i;
 	struct ref *posn;
 	struct strbuf buf = STRBUF_INIT;
@@ -139,10 +157,16 @@ static int fetch_with_import(struct transport *transport,
 	finish_command(&fastimport);
 
 	for (i = 0; i < nr_heads; i++) {
+		char *private;
 		posn = to_fetch[i];
 		if (posn->status & REF_STATUS_UPTODATE)
 			continue;
-		read_ref(posn->name, posn->old_sha1);
+		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);
 	}
 	return 0;
 }
-- 
1.6.5.2.158.g6dacb

[PATCH v3 09/12] Allow helpers to report in "list" command that the ref is unchanged

[Sverre Rabbelier]

From: Daniel Barkalow <barkalow@iabervon.org>

Helpers may use a line like "? name unchanged" to specify that there
is nothing new at that name, without any git-specific code to
determine the correct response.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
---

	Unchanged.

 Documentation/git-remote-helpers.txt |    4 +++-
 transport-helper.c                   |   22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletions(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index e9aa67e..2c5130f 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -70,7 +70,9 @@ CAPABILITIES
 REF LIST ATTRIBUTES
 -------------------
 
-None are defined yet, but the caller must accept any which are supplied.
+'unchanged'::
+	This ref is unchanged since the last import or fetch, although
+	the helper cannot necessarily determine what value that produced.
 
 Documentation
 -------------
diff --git a/transport-helper.c b/transport-helper.c
index c4ab84a..d38dedf 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -194,6 +194,22 @@ static int fetch(struct transport *transport,
 	return -1;
 }
 
+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 child_process *helper;
@@ -228,6 +244,12 @@ 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);
 	}
 	strbuf_release(&buf);
-- 
1.6.5.2.158.g6dacb

[PATCH v3 10/12] Allow helpers to request the path to the .git directory

[Sverre Rabbelier]

The 'gitdir' capability is reported by the remote helper if it
requires the location of the .git directory. The location of the .git
directory can then be used by the helper to store status files even
when the current directory is not a git repository (such as is the
case when cloning).

The location of the .git dir is specified as an absolute path.

Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Rebased, but otherwise unchanged.
	Needs to be updated when we decide on a proper location for
	the helper specific info.

 transport-helper.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/transport-helper.c b/transport-helper.c
index d38dedf..7ea76fd 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -64,6 +64,12 @@ static struct child_process *get_helper(struct transport *transport)
 				   refspec_alloc);
 			refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
 		}
+		if (!strcmp(buf.buf, "gitdir")) {
+			struct strbuf gitdir = STRBUF_INIT;
+			strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
+			write_in_full(helper->in, gitdir.buf, gitdir.len);
+			strbuf_reset(&gitdir);
+		}
 	}
 	if (refspecs) {
 		data->refspec_nr = refspec_nr;
-- 
1.6.5.2.158.g6dacb

[PATCH v3 11/12] Basic build infrastructure for Python scripts

[Sverre Rabbelier]

From: Johan Herland <johan@herland.net>

This patch adds basic boilerplate support (based on corresponding Perl
sections) for enabling the building and installation Python scripts.

There are currently no Python scripts being built, and when Python
scripts are added in future patches, their building and installation
can be disabled by defining NO_PYTHON.

Signed-off-by: Johan Herland <johan@herland.net>
---

	Unchanged.

 Makefile      |   13 +++++++++++++
 configure.ac  |    3 +++
 t/test-lib.sh |    1 +
 3 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 5d5976f..6d1593f 100644
--- a/Makefile
+++ b/Makefile
@@ -168,6 +168,8 @@ all::
 #
 # Define NO_PERL if you do not want Perl scripts or libraries at all.
 #
+# Define NO_PYTHON if you do not want Python scripts or libraries at all.
+#
 # Define NO_TCLTK if you do not want Tcl/Tk GUI.
 #
 # The TCL_PATH variable governs the location of the Tcl interpreter
@@ -312,6 +314,7 @@ LIB_H =
 LIB_OBJS =
 PROGRAMS =
 SCRIPT_PERL =
+SCRIPT_PYTHON =
 SCRIPT_SH =
 TEST_PROGRAMS =
 
@@ -349,6 +352,7 @@ SCRIPT_PERL += git-svn.perl
 
 SCRIPTS = $(patsubst %.sh,%,$(SCRIPT_SH)) \
 	  $(patsubst %.perl,%,$(SCRIPT_PERL)) \
+	  $(patsubst %.py,%,$(SCRIPT_PYTHON)) \
 	  git-instaweb
 
 # Empty...
@@ -402,8 +406,12 @@ endif
 ifndef PERL_PATH
 	PERL_PATH = /usr/bin/perl
 endif
+ifndef PYTHON_PATH
+	PYTHON_PATH = /usr/bin/python
+endif
 
 export PERL_PATH
+export PYTHON_PATH
 
 LIB_FILE=libgit.a
 XDIFF_LIB=xdiff/lib.a
@@ -1315,6 +1323,10 @@ ifeq ($(PERL_PATH),)
 NO_PERL=NoThanks
 endif
 
+ifeq ($(PYTHON_PATH),)
+NO_PYTHON=NoThanks
+endif
+
 QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
 QUIET_SUBDIR1  =
 
@@ -1362,6 +1374,7 @@ prefix_SQ = $(subst ','\'',$(prefix))
 
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
+PYTHON_PATH_SQ = $(subst ','\'',$(PYTHON_PATH))
 TCLTK_PATH_SQ = $(subst ','\'',$(TCLTK_PATH))
 
 LIBS = $(GITLIBS) $(EXTLIBS)
diff --git a/configure.ac b/configure.ac
index b09b8e4..84b6cf4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -233,6 +233,9 @@ GIT_ARG_SET_PATH(shell)
 # Define PERL_PATH to provide path to Perl.
 GIT_ARG_SET_PATH(perl)
 #
+# Define PYTHON_PATH to provide path to Python.
+GIT_ARG_SET_PATH(python)
+#
 # Define ZLIB_PATH to provide path to zlib.
 GIT_ARG_SET_PATH(zlib)
 #
diff --git a/t/test-lib.sh b/t/test-lib.sh
index f2ca536..0b991db 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -729,6 +729,7 @@ case $(uname -s) in
 esac
 
 test -z "$NO_PERL" && test_set_prereq PERL
+test -z "$NO_PYTHON" && test_set_prereq PYTHON
 
 # test whether the filesystem supports symbolic links
 ln -s x y 2>/dev/null && test -h y 2>/dev/null && test_set_prereq SYMLINKS
-- 
1.6.5.2.158.g6dacb

[PATCH v3 12/12] Add Python support library for remote helpers

[Sverre Rabbelier]

This patch introduces parts of a Python package called
"git_remote_helpers" containing the building blocks for
remote helpers written in Python.

No actual remote helpers are part of this patch, this patch only
includes the common basics needed to start writing such helpers.

The patch includes the necessary Makefile additions to build and
install the git_remote_helpers Python package along with the rest of
Git.

This patch is based on Johan Herland's git_remote_cvs patch and
has been improved by the following contributions:
- David Aguilar: Lots of Python coding style fixes
- David Aguilar: DESTDIR support in Makefile

Cc: David Aguilar <davvid@gmail.com>
Cc: Johan Herland <johan@herland.net>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

	Fixed commit msg as per Johan's suggestions.

 Makefile                           |   38 ++
 git_remote_helpers/.gitignore      |    2 +
 git_remote_helpers/Makefile        |   35 ++
 git_remote_helpers/__init__.py     |   16 +
 git_remote_helpers/git/git.py      |  678 ++++++++++++++++++++++++++++++++++++
 git_remote_helpers/setup.py        |   17 +
 git_remote_helpers/util.py         |  194 ++++++++++
 t/test-lib.sh                      |    9 +
 8 files changed, 989 insertions(+), 0 deletions(-)
 create mode 100644 git_remote_helpers/.gitignore
 create mode 100644 git_remote_helpers/Makefile
 create mode 100644 git_remote_helpers/__init__.py
 create mode 100644 git_remote_helpers/git/__init__.py
 create mode 100644 git_remote_helpers/git/git.py
 create mode 100644 git_remote_helpers/setup.py
 create mode 100644 git_remote_helpers/util.py

diff --git a/Makefile b/Makefile
index 6d1593f..701439f 100644
--- a/Makefile
+++ b/Makefile
@@ -1406,6 +1406,9 @@ endif
 ifndef NO_PERL
 	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' all
 endif
+ifndef NO_PYTHON
+	$(QUIET_SUBDIR0)git_remote_helpers $(QUIET_SUBDIR1) PYTHON_PATH='$(PYTHON_PATH_SQ)' prefix='$(prefix_SQ)' all
+endif
 	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1)
 
 please_set_SHELL_PATH_to_a_more_modern_shell:
@@ -1524,6 +1527,35 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
 	mv $@+ $@
 endif # NO_PERL
 
+ifndef NO_PYTHON
+$(patsubst %.py,%,$(SCRIPT_PYTHON)): GIT-CFLAGS
+$(patsubst %.py,%,$(SCRIPT_PYTHON)): % : %.py
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C git_remote_helpers -s \
+		--no-print-directory prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' \
+		instlibdir` && \
+	sed -e '1{' \
+	    -e '	s|#!.*python|#!$(PYTHON_PATH_SQ)|' \
+	    -e '}' \
+	    -e 's|^import sys.*|&; \\\
+	           import os; \\\
+	           sys.path[0] = os.environ.has_key("GITPYTHONLIB") and \\\
+	                         os.environ["GITPYTHONLIB"] or \\\
+	                         "@@INSTLIBDIR@@"|' \
+	    -e 's|@@INSTLIBDIR@@|'"$$INSTLIBDIR"'|g' \
+	    $@.py >$@+ && \
+	chmod +x $@+ && \
+	mv $@+ $@
+else # NO_PYTHON
+$(patsubst %.py,%,$(SCRIPT_PYTHON)): % : unimplemented.sh
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
+	    -e 's|@@REASON@@|NO_PYTHON=$(NO_PYTHON)|g' \
+	    unimplemented.sh >$@+ && \
+	chmod +x $@+ && \
+	mv $@+ $@
+endif # NO_PYTHON
+
 configure: configure.ac
 	$(QUIET_GEN)$(RM) $@ $<+ && \
 	sed -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
@@ -1748,6 +1780,9 @@ install: all
 ifndef NO_PERL
 	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
 endif
+ifndef NO_PYTHON
+	$(MAKE) -C git_remote_helpers prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
+endif
 ifndef NO_TCLTK
 	$(MAKE) -C gitk-git install
 	$(MAKE) -C git-gui gitexecdir='$(gitexec_instdir_SQ)' install
@@ -1862,6 +1897,9 @@ ifndef NO_PERL
 	$(RM) gitweb/gitweb.cgi
 	$(MAKE) -C perl clean
 endif
+ifndef NO_PYTHON
+	$(MAKE) -C git_remote_helpers clean
+endif
 	$(MAKE) -C templates/ clean
 	$(MAKE) -C t/ clean
 ifndef NO_TCLTK
diff --git a/git_remote_helpers/.gitignore b/git_remote_helpers/.gitignore
new file mode 100644
index 0000000..2247d5f
--- /dev/null
+++ b/git_remote_helpers/.gitignore
@@ -0,0 +1,2 @@
+/build
+/dist
diff --git a/git_remote_helpers/Makefile b/git_remote_helpers/Makefile
new file mode 100644
index 0000000..c62dfd0
--- /dev/null
+++ b/git_remote_helpers/Makefile
@@ -0,0 +1,35 @@
+#
+# Makefile for the git_remote_helpers python support modules
+#
+pysetupfile:=setup.py
+
+# Shell quote (do not use $(call) to accommodate ancient setups);
+DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
+
+ifndef PYTHON_PATH
+	PYTHON_PATH = /usr/bin/python
+endif
+ifndef prefix
+	prefix = $(HOME)
+endif
+ifndef V
+	QUIET = @
+	QUIETSETUP = --quiet
+endif
+
+PYLIBDIR=$(shell $(PYTHON_PATH) -c \
+	 "import sys; \
+	 print 'lib/python%i.%i/site-packages' % sys.version_info[:2]")
+
+all: $(pysetupfile)
+	$(QUIET)$(PYTHON_PATH) $(pysetupfile) $(QUIETSETUP) build
+
+install: $(pysetupfile)
+	$(PYTHON_PATH) $(pysetupfile) install --prefix $(DESTDIR_SQ)$(prefix)
+
+instlibdir: $(pysetupfile)
+	@echo "$(DESTDIR_SQ)$(prefix)/$(PYLIBDIR)"
+
+clean:
+	$(QUIET)$(PYTHON_PATH) $(pysetupfile) $(QUIETSETUP) clean -a
+	$(RM) *.pyo *.pyc
diff --git a/git_remote_helpers/__init__.py b/git_remote_helpers/__init__.py
new file mode 100644
index 0000000..00f69cb
--- /dev/null
+++ b/git_remote_helpers/__init__.py
@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+"""Support library package for git remote helpers.
+
+Git remote helpers are helper commands that interfaces with a non-git
+repository to provide automatic import of non-git history into a Git
+repository.
+
+This package provides the support library needed by these helpers..
+The following modules are included:
+
+- git.git - Interaction with Git repositories
+
+- util - General utility functionality use by the other modules in
+         this package, and also used directly by the helpers.
+"""
diff --git a/git_remote_helpers/git/__init__.py b/git_remote_helpers/git/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/git_remote_helpers/git/git.py b/git_remote_helpers/git/git.py
new file mode 100644
index 0000000..a383e6c
--- /dev/null
+++ b/git_remote_helpers/git/git.py
@@ -0,0 +1,678 @@
+#!/usr/bin/env python
+
+"""Functionality for interacting with Git repositories.
+
+This module provides classes for interfacing with a Git repository.
+"""
+
+import os
+import re
+import time
+from binascii import hexlify
+from cStringIO import StringIO
+import unittest
+
+from git_remote_helpers.util import debug, error, die, start_command, run_command
+
+
+def get_git_dir ():
+    """Return the path to the GIT_DIR for this repo."""
+    args = ("git", "rev-parse", "--git-dir")
+    exit_code, output, errors = run_command(args)
+    if exit_code:
+        die("Failed to retrieve git dir")
+    assert not errors
+    return output.strip()
+
+
+def parse_git_config ():
+    """Return a dict containing the parsed version of 'git config -l'."""
+    exit_code, output, errors = run_command(("git", "config", "-z", "-l"))
+    if exit_code:
+        die("Failed to retrieve git configuration")
+    assert not errors
+    return dict([e.split('\n', 1) for e in output.split("\0") if e])
+
+
+def git_config_bool (value):
+    """Convert the given git config string value to True or False.
+
+    Raise ValueError if the given string was not recognized as a
+    boolean value.
+
+    """
+    norm_value = str(value).strip().lower()
+    if norm_value in ("true", "1", "yes", "on", ""):
+        return True
+    if norm_value in ("false", "0", "no", "off", "none"):
+        return False
+    raise ValueError("Failed to parse '%s' into a boolean value" % (value))
+
+
+def valid_git_ref (ref_name):
+    """Return True iff the given ref name is a valid git ref name."""
+    # The following is a reimplementation of the git check-ref-format
+    # command.  The rules were derived from the git check-ref-format(1)
+    # manual page.  This code should be replaced by a call to
+    # check_ref_format() in the git library, when such is available.
+    if ref_name.endswith('/') or \
+       ref_name.startswith('.') or \
+       ref_name.count('/.') or \
+       ref_name.count('..') or \
+       ref_name.endswith('.lock'):
+        return False
+    for c in ref_name:
+        if ord(c) < 0x20 or ord(c) == 0x7f or c in " ~^:?*[":
+            return False
+    return True
+
+
+class GitObjectFetcher(object):
+
+    """Provide parsed access to 'git cat-file --batch'.
+
+    This provides a read-only interface to the Git object database.
+
+    """
+
+    def __init__ (self):
+        """Initiate a 'git cat-file --batch' session."""
+        self.queue = []  # List of object names to be submitted
+        self.in_transit = None  # Object name currently in transit
+
+        # 'git cat-file --batch' produces binary output which is likely
+        # to be corrupted by the default "rU"-mode pipe opened by
+        # start_command.  (Mode == "rU" does universal new-line
+        # conversion, which mangles carriage returns.) Therefore, we
+        # open an explicitly binary-safe pipe for transferring the
+        # output from 'git cat-file --batch'.
+        pipe_r_fd, pipe_w_fd = os.pipe()
+        pipe_r = os.fdopen(pipe_r_fd, "rb")
+        pipe_w = os.fdopen(pipe_w_fd, "wb")
+        self.proc = start_command(("git", "cat-file", "--batch"),
+                                  stdout = pipe_w)
+        self.f = pipe_r
+
+    def __del__ (self):
+        """Verify completed communication with 'git cat-file --batch'."""
+        assert not self.queue
+        assert self.in_transit is None
+        self.proc.stdin.close()
+        assert self.proc.wait() == 0  # Zero exit code
+        assert self.f.read() == ""  # No remaining output
+
+    def _submit_next_object (self):
+        """Submit queue items to the 'git cat-file --batch' process.
+
+        If there are items in the queue, and there is currently no item
+        currently in 'transit', then pop the first item off the queue,
+        and submit it.
+
+        """
+        if self.queue and self.in_transit is None:
+            self.in_transit = self.queue.pop(0)
+            print >> self.proc.stdin, self.in_transit[0]
+
+    def push (self, obj, callback):
+        """Push the given object name onto the queue.
+
+        The given callback function will at some point in the future
+        be called exactly once with the following arguments:
+        - self - this GitObjectFetcher instance
+        - obj  - the object name provided to push()
+        - sha1 - the SHA1 of the object, if 'None' obj is missing
+        - t    - the type of the object (tag/commit/tree/blob)
+        - size - the size of the object in bytes
+        - data - the object contents
+
+        """
+        self.queue.append((obj, callback))
+        self._submit_next_object()  # (Re)start queue processing
+
+    def process_next_entry (self):
+        """Read the next entry off the queue and invoke callback."""
+        obj, cb = self.in_transit
+        self.in_transit = None
+        header = self.f.readline()
+        if header == "%s missing\n" % (obj):
+            cb(self, obj, None, None, None, None)
+            return
+        sha1, t, size = header.split(" ")
+        assert len(sha1) == 40
+        assert t in ("tag", "commit", "tree", "blob")
+        assert size.endswith("\n")
+        size = int(size.strip())
+        data = self.f.read(size)
+        assert self.f.read(1) == "\n"
+        cb(self, obj, sha1, t, size, data)
+        self._submit_next_object()
+
+    def process (self):
+        """Process the current queue until empty."""
+        while self.in_transit is not None:
+            self.process_next_entry()
+
+    # High-level convenience methods:
+
+    def get_sha1 (self, objspec):
+        """Return the SHA1 of the object specified by 'objspec'.
+
+        Return None if 'objspec' does not specify an existing object.
+
+        """
+        class _ObjHandler(object):
+            """Helper class for getting the returned SHA1."""
+            def __init__ (self, parser):
+                self.parser = parser
+                self.sha1 = None
+
+            def __call__ (self, parser, obj, sha1, t, size, data):
+                # FIXME: Many unused arguments. Could this be cheaper?
+                assert parser == self.parser
+                self.sha1 = sha1
+
+        handler = _ObjHandler(self)
+        self.push(objspec, handler)
+        self.process()
+        return handler.sha1
+
+    def open_obj (self, objspec):
+        """Return a file object wrapping the contents of a named object.
+
+        The caller is responsible for calling .close() on the returned
+        file object.
+
+        Raise KeyError if 'objspec' does not exist in the repo.
+
+        """
+        class _ObjHandler(object):
+            """Helper class for parsing the returned git object."""
+            def __init__ (self, parser):
+                """Set up helper."""
+                self.parser = parser
+                self.contents = StringIO()
+                self.err = None
+
+            def __call__ (self, parser, obj, sha1, t, size, data):
+                """Git object callback (see GitObjectFetcher documentation)."""
+                assert parser == self.parser
+                if not sha1:  # Missing object
+                    self.err = "Missing object '%s'" % obj
+                else:
+                    assert size == len(data)
+                    self.contents.write(data)
+
+        handler = _ObjHandler(self)
+        self.push(objspec, handler)
+        self.process()
+        if handler.err:
+            raise KeyError(handler.err)
+        handler.contents.seek(0)
+        return handler.contents
+
+    def walk_tree (self, tree_objspec, callback, prefix = ""):
+        """Recursively walk the given Git tree object.
+
+        Recursively walk all subtrees of the given tree object, and
+        invoke the given callback passing three arguments:
+        (path, mode, data) with the path, permission bits, and contents
+        of all the blobs found in the entire tree structure.
+
+        """
+        class _ObjHandler(object):
+            """Helper class for walking a git tree structure."""
+            def __init__ (self, parser, cb, path, mode = None):
+                """Set up helper."""
+                self.parser = parser
+                self.cb = cb
+                self.path = path
+                self.mode = mode
+                self.err = None
+
+            def parse_tree (self, treedata):
+                """Parse tree object data, yield tree entries.
+
+                Each tree entry is a 3-tuple (mode, sha1, path)
+
+                self.path is prepended to all paths yielded
+                from this method.
+
+                """
+                while treedata:
+                    mode = int(treedata[:6], 10)
+                    # Turn 100xxx into xxx
+                    if mode > 100000:
+                        mode -= 100000
+                    assert treedata[6] == " "
+                    i = treedata.find("\0", 7)
+                    assert i > 0
+                    path = treedata[7:i]
+                    sha1 = hexlify(treedata[i + 1: i + 21])
+                    yield (mode, sha1, self.path + path)
+                    treedata = treedata[i + 21:]
+
+            def __call__ (self, parser, obj, sha1, t, size, data):
+                """Git object callback (see GitObjectFetcher documentation)."""
+                assert parser == self.parser
+                if not sha1:  # Missing object
+                    self.err = "Missing object '%s'" % (obj)
+                    return
+                assert size == len(data)
+                if t == "tree":
+                    if self.path:
+                        self.path += "/"
+                    # Recurse into all blobs and subtrees
+                    for m, s, p in self.parse_tree(data):
+                        parser.push(s,
+                                    self.__class__(self.parser, self.cb, p, m))
+                elif t == "blob":
+                    self.cb(self.path, self.mode, data)
+                else:
+                    raise ValueError("Unknown object type '%s'" % (t))
+
+        self.push(tree_objspec, _ObjHandler(self, callback, prefix))
+        self.process()
+
+
+class GitRefMap(object):
+
+    """Map Git ref names to the Git object names they currently point to.
+
+    Behaves like a dictionary of Git ref names -> Git object names.
+
+    """
+
+    def __init__ (self, obj_fetcher):
+        """Create a new Git ref -> object map."""
+        self.obj_fetcher = obj_fetcher
+        self._cache = {}  # dict: refname -> objname
+
+    def _load (self, ref):
+        """Retrieve the object currently bound to the given ref.
+
+        The name of the object pointed to by the given ref is stored
+        into this mapping, and also returned.
+
+        """
+        if ref not in self._cache:
+            self._cache[ref] = self.obj_fetcher.get_sha1(ref)
+        return self._cache[ref]
+
+    def __contains__ (self, refname):
+        """Return True if the given refname is present in this cache."""
+        return bool(self._load(refname))
+
+    def __getitem__ (self, refname):
+        """Return the git object name pointed to by the given refname."""
+        commit = self._load(refname)
+        if commit is None:
+            raise KeyError("Unknown ref '%s'" % (refname))
+        return commit
+
+    def get (self, refname, default = None):
+        """Return the git object name pointed to by the given refname."""
+        commit = self._load(refname)
+        if commit is None:
+            return default
+        return commit
+
+
+class GitFICommit(object):
+
+    """Encapsulate the data in a Git fast-import commit command."""
+
+    SHA1RE = re.compile(r'^[0-9a-f]{40}$')
+
+    @classmethod
+    def parse_mode (cls, mode):
+        """Verify the given git file mode, and return it as a string."""
+        assert mode in (644, 755, 100644, 100755, 120000)
+        return "%i" % (mode)
+
+    @classmethod
+    def parse_objname (cls, objname):
+        """Return the given object name (or mark number) as a string."""
+        if isinstance(objname, int):  # Object name is a mark number
+            assert objname > 0
+            return ":%i" % (objname)
+
+        # No existence check is done, only checks for valid format
+        assert cls.SHA1RE.match(objname)  # Object name is valid SHA1
+        return objname
+
+    @classmethod
+    def quote_path (cls, path):
+        """Return a quoted version of the given path."""
+        path = path.replace("\\", "\\\\")
+        path = path.replace("\n", "\\n")
+        path = path.replace('"', '\\"')
+        return '"%s"' % (path)
+
+    @classmethod
+    def parse_path (cls, path):
+        """Verify that the given path is valid, and quote it, if needed."""
+        assert not isinstance(path, int)  # Cannot be a mark number
+
+        # These checks verify the rules on the fast-import man page
+        assert not path.count("//")
+        assert not path.endswith("/")
+        assert not path.startswith("/")
+        assert not path.count("/./")
+        assert not path.count("/../")
+        assert not path.endswith("/.")
+        assert not path.endswith("/..")
+        assert not path.startswith("./")
+        assert not path.startswith("../")
+
+        if path.count('"') + path.count('\n') + path.count('\\'):
+            return cls.quote_path(path)
+        return path
+
+    def __init__ (self, name, email, timestamp, timezone, message):
+        """Create a new Git fast-import commit, with the given metadata."""
+        self.name = name
+        self.email = email
+        self.timestamp = timestamp
+        self.timezone = timezone
+        self.message = message
+        self.pathops = []  # List of path operations in this commit
+
+    def modify (self, mode, blobname, path):
+        """Add a file modification to this Git fast-import commit."""
+        self.pathops.append(("M",
+                             self.parse_mode(mode),
+                             self.parse_objname(blobname),
+                             self.parse_path(path)))
+
+    def delete (self, path):
+        """Add a file deletion to this Git fast-import commit."""
+        self.pathops.append(("D", self.parse_path(path)))
+
+    def copy (self, path, newpath):
+        """Add a file copy to this Git fast-import commit."""
+        self.pathops.append(("C",
+                             self.parse_path(path),
+                             self.parse_path(newpath)))
+
+    def rename (self, path, newpath):
+        """Add a file rename to this Git fast-import commit."""
+        self.pathops.append(("R",
+                             self.parse_path(path),
+                             self.parse_path(newpath)))
+
+    def note (self, blobname, commit):
+        """Add a note object to this Git fast-import commit."""
+        self.pathops.append(("N",
+                             self.parse_objname(blobname),
+                             self.parse_objname(commit)))
+
+    def deleteall (self):
+        """Delete all files in this Git fast-import commit."""
+        self.pathops.append("deleteall")
+
+
+class TestGitFICommit(unittest.TestCase):
+
+    """GitFICommit selftests."""
+
+    def test_basic (self):
+        """GitFICommit basic selftests."""
+
+        def expect_fail (method, data):
+            """Verify that the method(data) raises an AssertionError."""
+            try:
+                method(data)
+            except AssertionError:
+                return
+            raise AssertionError("Failed test for invalid data '%s(%s)'" %
+                                 (method.__name__, repr(data)))
+
+    def test_parse_mode (self):
+        """GitFICommit.parse_mode() selftests."""
+        self.assertEqual(GitFICommit.parse_mode(644), "644")
+        self.assertEqual(GitFICommit.parse_mode(755), "755")
+        self.assertEqual(GitFICommit.parse_mode(100644), "100644")
+        self.assertEqual(GitFICommit.parse_mode(100755), "100755")
+        self.assertEqual(GitFICommit.parse_mode(120000), "120000")
+        self.assertRaises(AssertionError, GitFICommit.parse_mode, 0)
+        self.assertRaises(AssertionError, GitFICommit.parse_mode, 123)
+        self.assertRaises(AssertionError, GitFICommit.parse_mode, 600)
+        self.assertRaises(AssertionError, GitFICommit.parse_mode, "644")
+        self.assertRaises(AssertionError, GitFICommit.parse_mode, "abc")
+
+    def test_parse_objname (self):
+        """GitFICommit.parse_objname() selftests."""
+        self.assertEqual(GitFICommit.parse_objname(1), ":1")
+        self.assertRaises(AssertionError, GitFICommit.parse_objname, 0)
+        self.assertRaises(AssertionError, GitFICommit.parse_objname, -1)
+        self.assertEqual(GitFICommit.parse_objname("0123456789" * 4),
+                         "0123456789" * 4)
+        self.assertEqual(GitFICommit.parse_objname("2468abcdef" * 4),
+                         "2468abcdef" * 4)
+        self.assertRaises(AssertionError, GitFICommit.parse_objname,
+                          "abcdefghij" * 4)
+
+    def test_parse_path (self):
+        """GitFICommit.parse_path() selftests."""
+        self.assertEqual(GitFICommit.parse_path("foo/bar"), "foo/bar")
+        self.assertEqual(GitFICommit.parse_path("path/with\n and \" in it"),
+                         '"path/with\\n and \\" in it"')
+        self.assertRaises(AssertionError, GitFICommit.parse_path, 1)
+        self.assertRaises(AssertionError, GitFICommit.parse_path, 0)
+        self.assertRaises(AssertionError, GitFICommit.parse_path, -1)
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo//bar")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "/foo/bar")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/./bar")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/../bar")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/.")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/..")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "./foo/bar")
+        self.assertRaises(AssertionError, GitFICommit.parse_path, "../foo/bar")
+
+
+class GitFastImport(object):
+
+    """Encapsulate communication with git fast-import."""
+
+    def __init__ (self, f, obj_fetcher, last_mark = 0):
+        """Set up self to communicate with a fast-import process through f."""
+        self.f = f  # File object where fast-import stream is written
+        self.obj_fetcher = obj_fetcher  # GitObjectFetcher instance
+        self.next_mark = last_mark + 1  # Next mark number
+        self.refs = set()  # Keep track of the refnames we've seen
+
+    def comment (self, s):
+        """Write the given comment in the fast-import stream."""
+        assert "\n" not in s, "Malformed comment: '%s'" % (s)
+        self.f.write("# %s\n" % (s))
+
+    def commit (self, ref, commitdata):
+        """Make a commit on the given ref, with the given GitFICommit.
+
+        Return the mark number identifying this commit.
+
+        """
+        self.f.write("""\
+commit %(ref)s
+mark :%(mark)i
+committer %(name)s <%(email)s> %(timestamp)i %(timezone)s
+data %(msgLength)i
+%(msg)s
+""" % {
+    'ref': ref,
+    'mark': self.next_mark,
+    'name': commitdata.name,
+    'email': commitdata.email,
+    'timestamp': commitdata.timestamp,
+    'timezone': commitdata.timezone,
+    'msgLength': len(commitdata.message),
+    'msg': commitdata.message,
+})
+
+        if ref not in self.refs:
+            self.refs.add(ref)
+            parent = ref + "^0"
+            if self.obj_fetcher.get_sha1(parent):
+                self.f.write("from %s\n" % (parent))
+
+        for op in commitdata.pathops:
+            self.f.write(" ".join(op))
+            self.f.write("\n")
+        self.f.write("\n")
+        retval = self.next_mark
+        self.next_mark += 1
+        return retval
+
+    def blob (self, data):
+        """Import the given blob.
+
+        Return the mark number identifying this blob.
+
+        """
+        self.f.write("blob\nmark :%i\ndata %i\n%s\n" %
+                     (self.next_mark, len(data), data))
+        retval = self.next_mark
+        self.next_mark += 1
+        return retval
+
+    def reset (self, ref, objname):
+        """Reset the given ref to point at the given Git object."""
+        self.f.write("reset %s\nfrom %s\n\n" %
+                     (ref, GitFICommit.parse_objname(objname)))
+        if ref not in self.refs:
+            self.refs.add(ref)
+
+
+class GitNotes(object):
+
+    """Encapsulate access to Git notes.
+
+    Simulates a dictionary of object name (SHA1) -> Git note mappings.
+
+    """
+
+    def __init__ (self, notes_ref, obj_fetcher):
+        """Create a new Git notes interface, bound to the given notes ref."""
+        self.notes_ref = notes_ref
+        self.obj_fetcher = obj_fetcher  # Used to get objects from repo
+        self.imports = []  # list: (objname, note data blob name) tuples
+
+    def __del__ (self):
+        """Verify that self.commit_notes() was called before destruction."""
+        if self.imports:
+            error("Missing call to self.commit_notes().")
+            error("%i notes are not committed!", len(self.imports))
+
+    def _load (self, objname):
+        """Return the note data associated with the given git object.
+
+        The note data is returned in string form. If no note is found
+        for the given object, None is returned.
+
+        """
+        try:
+            f = self.obj_fetcher.open_obj("%s:%s" % (self.notes_ref, objname))
+            ret = f.read()
+            f.close()
+        except KeyError:
+            ret = None
+        return ret
+
+    def __getitem__ (self, objname):
+        """Return the note contents associated with the given object.
+
+        Raise KeyError if given object has no associated note.
+
+        """
+        blobdata = self._load(objname)
+        if blobdata is None:
+            raise KeyError("Object '%s' has no note" % (objname))
+        return blobdata
+
+    def get (self, objname, default = None):
+        """Return the note contents associated with the given object.
+
+        Return given default if given object has no associated note.
+
+        """
+        blobdata = self._load(objname)
+        if blobdata is None:
+            return default
+        return blobdata
+
+    def import_note (self, objname, data, gfi):
+        """Tell git fast-import to store data as a note for objname.
+
+        This method uses the given GitFastImport object to create a
+        blob containing the given note data.  Also an entry mapping the
+        given object name to the created blob is stored until
+        commit_notes() is called.
+
+        Note that this method only works if it is later followed by a
+        call to self.commit_notes() (which produces the note commit
+        that refers to the blob produced here).
+
+        """
+        if not data.endswith("\n"):
+            data += "\n"
+        gfi.comment("Importing note for object %s" % (objname))
+        mark = gfi.blob(data)
+        self.imports.append((objname, mark))
+
+    def commit_notes (self, gfi, author, message):
+        """Produce a git fast-import note commit for the imported notes.
+
+        This method uses the given GitFastImport object to create a
+        commit on the notes ref, introducing the notes previously
+        submitted to import_note().
+
+        """
+        if not self.imports:
+            return
+        commitdata = GitFICommit(author[0], author[1],
+                                 time.time(), "0000", message)
+        for objname, blobname in self.imports:
+            assert isinstance(objname, int) and objname > 0
+            assert isinstance(blobname, int) and blobname > 0
+            commitdata.note(blobname, objname)
+        gfi.commit(self.notes_ref, commitdata)
+        self.imports = []
+
+
+class GitCachedNotes(GitNotes):
+
+    """Encapsulate access to Git notes (cached version).
+
+    Only use this class if no caching is done at a higher level.
+
+    Simulates a dictionary of object name (SHA1) -> Git note mappings.
+
+    """
+
+    def __init__ (self, notes_ref, obj_fetcher):
+        """Set up a caching wrapper around GitNotes."""
+        GitNotes.__init__(self, notes_ref, obj_fetcher)
+        self._cache = {}  # Cache: object name -> note data
+
+    def __del__ (self):
+        """Verify that GitNotes' destructor is called."""
+        GitNotes.__del__(self)
+
+    def _load (self, objname):
+        """Extend GitNotes._load() with a local objname -> note cache."""
+        if objname not in self._cache:
+            self._cache[objname] = GitNotes._load(self, objname)
+        return self._cache[objname]
+
+    def import_note (self, objname, data, gfi):
+        """Extend GitNotes.import_note() with a local objname -> note cache."""
+        if not data.endswith("\n"):
+            data += "\n"
+        assert objname not in self._cache
+        self._cache[objname] = data
+        GitNotes.import_note(self, objname, data, gfi)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/git_remote_helpers/setup.py b/git_remote_helpers/setup.py
new file mode 100644
index 0000000..4d434b6
--- /dev/null
+++ b/git_remote_helpers/setup.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+
+"""Distutils build/install script for the git_remote_helpers package."""
+
+from distutils.core import setup
+
+setup(
+    name = 'git_remote_helpers',
+    version = '0.1.0',
+    description = 'Git remote helper program for non-git repositories',
+    license = 'GPLv2',
+    author = 'The Git Community',
+    author_email = 'git@vger.kernel.org',
+    url = 'http://www.git-scm.com/',
+    package_dir = {'git_remote_helpers': ''},
+    packages = ['git_remote_helpers', 'git_remote_helpers.git'],
+)
diff --git a/git_remote_helpers/util.py b/git_remote_helpers/util.py
new file mode 100644
index 0000000..dce83e6
--- /dev/null
+++ b/git_remote_helpers/util.py
@@ -0,0 +1,194 @@
+#!/usr/bin/env python
+
+"""Misc. useful functionality used by the rest of this package.
+
+This module provides common functionality used by the other modules in
+this package.
+
+"""
+
+import sys
+import os
+import subprocess
+
+
+# Whether or not to show debug messages
+DEBUG = False
+
+def notify(msg, *args):
+    """Print a message to stderr."""
+    print >> sys.stderr, msg % args
+
+def debug (msg, *args):
+    """Print a debug message to stderr when DEBUG is enabled."""
+    if DEBUG:
+        print >> sys.stderr, msg % args
+
+def error (msg, *args):
+    """Print an error message to stderr."""
+    print >> sys.stderr, "ERROR:", msg % args
+
+def warn(msg, *args):
+    """Print a warning message to stderr."""
+    print >> sys.stderr, "warning:", msg % args
+
+def die (msg, *args):
+    """Print as error message to stderr and exit the program."""
+    error(msg, *args)
+    sys.exit(1)
+
+
+class ProgressIndicator(object):
+
+    """Simple progress indicator.
+
+    Displayed as a spinning character by default, but can be customized
+    by passing custom messages that overrides the spinning character.
+
+    """
+
+    States = ("|", "/", "-", "\\")
+
+    def __init__ (self, prefix = "", f = sys.stdout):
+        """Create a new ProgressIndicator, bound to the given file object."""
+        self.n = 0  # Simple progress counter
+        self.f = f  # Progress is written to this file object
+        self.prev_len = 0  # Length of previous msg (to be overwritten)
+        self.prefix = prefix  # Prefix prepended to each progress message
+        self.prefix_lens = [] # Stack of prefix string lengths
+
+    def pushprefix (self, prefix):
+        """Append the given prefix onto the prefix stack."""
+        self.prefix_lens.append(len(self.prefix))
+        self.prefix += prefix
+
+    def popprefix (self):
+        """Remove the last prefix from the prefix stack."""
+        prev_len = self.prefix_lens.pop()
+        self.prefix = self.prefix[:prev_len]
+
+    def __call__ (self, msg = None, lf = False):
+        """Indicate progress, possibly with a custom message."""
+        if msg is None:
+            msg = self.States[self.n % len(self.States)]
+        msg = self.prefix + msg
+        print >> self.f, "\r%-*s" % (self.prev_len, msg),
+        self.prev_len = len(msg.expandtabs())
+        if lf:
+            print >> self.f
+            self.prev_len = 0
+        self.n += 1
+
+    def finish (self, msg = "done", noprefix = False):
+        """Finalize progress indication with the given message."""
+        if noprefix:
+            self.prefix = ""
+        self(msg, True)
+
+
+def start_command (args, cwd = None, shell = False, add_env = None,
+                   stdin = subprocess.PIPE, stdout = subprocess.PIPE,
+                   stderr = subprocess.PIPE):
+    """Start the given command, and return a subprocess object.
+
+    This provides a simpler interface to the subprocess module.
+
+    """
+    env = None
+    if add_env is not None:
+        env = os.environ.copy()
+        env.update(add_env)
+    return subprocess.Popen(args, bufsize = 1, stdin = stdin, stdout = stdout,
+                            stderr = stderr, cwd = cwd, shell = shell,
+                            env = env, universal_newlines = True)
+
+
+def run_command (args, cwd = None, shell = False, add_env = None,
+                 flag_error = True):
+    """Run the given command to completion, and return its results.
+
+    This provides a simpler interface to the subprocess module.
+
+    The results are formatted as a 3-tuple: (exit_code, output, errors)
+
+    If flag_error is enabled, Error messages will be produced if the
+    subprocess terminated with a non-zero exit code and/or stderr
+    output.
+
+    The other arguments are passed on to start_command().
+
+    """
+    process = start_command(args, cwd, shell, add_env)
+    (output, errors) = process.communicate()
+    exit_code = process.returncode
+    if flag_error and errors:
+        error("'%s' returned errors:\n---\n%s---", " ".join(args), errors)
+    if flag_error and exit_code:
+        error("'%s' returned exit code %i", " ".join(args), exit_code)
+    return (exit_code, output, errors)
+
+
+def file_reader_method (missing_ok = False):
+    """Decorator for simplifying reading of files.
+
+    If missing_ok is True, a failure to open a file for reading will
+    not raise the usual IOError, but instead the wrapped method will be
+    called with f == None.  The method must in this case properly
+    handle f == None.
+
+    """
+    def _wrap (method):
+        """Teach given method to handle both filenames and file objects.
+
+        The given method must take a file object as its second argument
+        (the first argument being 'self', of course).  This decorator
+        will take a filename given as the second argument and promote
+        it to a file object.
+
+        """
+        def _wrapped_method (self, filename, *args, **kwargs):
+            if isinstance(filename, file):
+                f = filename
+            else:
+                try:
+                    f = open(filename, 'r')
+                except IOError:
+                    if missing_ok:
+                        f = None
+                    else:
+                        raise
+            try:
+                return method(self, f, *args, **kwargs)
+            finally:
+                if not isinstance(filename, file) and f:
+                    f.close()
+        return _wrapped_method
+    return _wrap
+
+
+def file_writer_method (method):
+    """Decorator for simplifying writing of files.
+
+    Enables the given method to handle both filenames and file objects.
+
+    The given method must take a file object as its second argument
+    (the first argument being 'self', of course).  This decorator will
+    take a filename given as the second argument and promote it to a
+    file object.
+
+    """
+    def _new_method (self, filename, *args, **kwargs):
+        if isinstance(filename, file):
+            f = filename
+        else:
+            # Make sure the containing directory exists
+            parent_dir = os.path.dirname(filename)
+            if not os.path.isdir(parent_dir):
+                os.makedirs(parent_dir)
+            f = open(filename, 'w')
+        try:
+            return method(self, f, *args, **kwargs)
+        finally:
+            if not isinstance(filename, file):
+                f.close()
+    return _new_method
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 0b991db..6ed5b28 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -638,6 +638,15 @@ test -d ../templates/blt || {
 	error "You haven't built things yet, have you?"
 }
 
+if test -z "$GIT_TEST_INSTALLED"
+then
+	GITPYTHONLIB="$(pwd)/../git_remote_helpers/build/lib"
+	export GITPYTHONLIB
+	test -d ../git_remote_helpers/build || {
+		error "You haven't built git_remote_helpers yet, have you?"
+	}
+fi
+
 if ! test -x ../test-chmtime; then
 	echo >&2 'You need to build test-chmtime:'
 	echo >&2 'Run "make test-chmtime" in the source (toplevel) directory'
-- 
1.6.5.2.158.g6dacb

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Daniel Barkalow]

On Fri, 6 Nov 2009, Sverre Rabbelier wrote:

> From: Daniel Barkalow <barkalow@iabervon.org>
> 
> This allows a helper to say that, when it handles "import
> refs/heads/topic", the script it outputs will actually write to
> refs/svn/origin/branches/topic; therefore, transport-helper should
> read it from the latter location after git-fast-import completes.
> ---
> 
> 	New in this series.
> 	Daniel, you did not include a S-o-b, I assume because you
> 	mean to add documentation?

I wasn't terribly convinced I'd actually implemented it correctly, since I 
couldn't test it essentially at all; I was just going for something that 
gave the right idea. 

At the very least, it needs documentation and memory leaks fixed (the 
refspec strings read from the helper, and the refspec structs and array on 
freeing the helper data).

Is this actually working with your helper? Occasionally I write code that 
just works without any testing, but I don't usually expect it. :)

	-Daniel
*This .sig left intentionally blank*

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Sverre Rabbelier]

Heya,

On Sat, Nov 7, 2009 at 00:12, Daniel Barkalow <barkalow@iabervon.org> wrote:
> At the very least, it needs documentation and memory leaks fixed (the
> refspec strings read from the helper, and the refspec structs and array on
> freeing the helper data).

Please send follow-ups against [0] and I will include them in the next round :).

> Is this actually working with your helper? Occasionally I write code that
> just works without any testing, but I don't usually expect it. :)

Not unless it has some very subtle bugs, it seems to work perfectly on
my helper.

[0] git://github.com/SRabbelier/git.git

-- 
Cheers,

Sverre Rabbelier

Re: [PATCH v3 11/12] Basic build infrastructure for Python scripts

[Andrzej K. Haczewski]

Hi,

2009/11/6 Sverre Rabbelier <srabbelier@gmail.com>:
> This patch adds basic boilerplate support (based on corresponding Perl
> sections) for enabling the building and installation Python scripts.
>
> There are currently no Python scripts being built, and when Python
> scripts are added in future patches, their building and installation
> can be disabled by defining NO_PYTHON.
>
> Signed-off-by: Johan Herland <johan@herland.net>

Does it mean, that it will be possible to write git-<cmd> scripts in
python or, in example, port bash and / or perl scripts to python?

I'm asking because bash+perl is a huge stopper for Windows platform,
which requires basic unix environment to work, while python support
for Windows is excellent and most of Windows developers already use
python.

--
Andrzej

Re: [PATCH v3 11/12] Basic build infrastructure for Python scripts

[Sverre Rabbelier]

Heya,

On Sat, Nov 7, 2009 at 00:23, Andrzej K. Haczewski <ahaczewski@gmail.com> wrote:
> Does it mean, that it will be possible to write git-<cmd> scripts in
> python or, in example, port bash and / or perl scripts to python?

Technically that would be possible yes.

> I'm asking because bash+perl is a huge stopper for Windows platform,
> which requires basic unix environment to work, while python support
> for Windows is excellent and most of Windows developers already use
> python.

I don't know what the stance is on this though, currently it is
intended only for the remote helpers I think.

-- 
Cheers,

Sverre Rabbelier

Re: [PATCH v3 11/12] Basic build infrastructure for Python scripts

[Johannes Schindelin]

Hi,

On Sat, 7 Nov 2009, Sverre Rabbelier wrote:

> On Sat, Nov 7, 2009 at 00:23, Andrzej K. Haczewski <ahaczewski@gmail.com> wrote:
> 
> > I'm asking because bash+perl is a huge stopper for Windows platform, 
> > which requires basic unix environment to work, while python support 
> > for Windows is excellent and most of Windows developers already use 
> > python.
> 
> I don't know what the stance is on this though, currently it is intended 
> only for the remote helpers I think.

Everybody who knows only a little bit about the history of msysGit knows 
that Perl/Bash support was easy while Python seems to be impossible.  
Before anybody says "but Python is Open Source, and available for 
Windows": I will only listen when you have a script that builds Python 
inside msysGit, not requiring a proprietary compiler nor Linux for a 
cross-build.

Hth,
Dscho

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Sverre Rabbelier]

Heya,

On Sat, Nov 7, 2009 at 00:19, Sverre Rabbelier <srabbelier@gmail.com> wrote:
> On Sat, Nov 7, 2009 at 00:12, Daniel Barkalow <barkalow@iabervon.org> wrote:
>> At the very least, it needs documentation and memory leaks fixed (the
>> refspec strings read from the helper, and the refspec structs and array on
>> freeing the helper data).
>
> Please send follow-ups against [0] and I will include them in the next round :).

It's in next now, so please send follow-ups against sr/vcs-helper.

-- 
Cheers,

Sverre Rabbelier

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Junio C Hamano]

Sverre Rabbelier <srabbelier@gmail.com> writes:

> Heya,
>
> On Sat, Nov 7, 2009 at 00:19, Sverre Rabbelier <srabbelier@gmail.com> wrote:
>> On Sat, Nov 7, 2009 at 00:12, Daniel Barkalow <barkalow@iabervon.org> wrote:
>>> At the very least, it needs documentation and memory leaks fixed (the
>>> refspec strings read from the helper, and the refspec structs and array on
>>> freeing the helper data).
>>
>> Please send follow-ups against [0] and I will include them in the next round :).
>
> It's in next now, so please send follow-ups against sr/vcs-helper.

Do you mean 'pu' or 'next'?

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Sverre Rabbelier]

Heya,

On Mon, Nov 9, 2009 at 17:44, Junio C Hamano <gitster@pobox.com> wrote:
> Sverre Rabbelier <srabbelier@gmail.com> writes:
>> It's in next now, so please send follow-ups against sr/vcs-helper.
>
> Do you mean 'pu' or 'next'?

Sorry, my hands did not type what my mind intended, I meant to say
'pu', apologies!

-- 
Cheers,

Sverre Rabbelier

Re: [PATCH v3 08/12] Allow helper to map private ref names into normal names

[Junio C Hamano]

Sverre Rabbelier <srabbelier@gmail.com> writes:

> Heya,
>
> On Mon, Nov 9, 2009 at 17:44, Junio C Hamano <gitster@pobox.com> wrote:
>> Sverre Rabbelier <srabbelier@gmail.com> writes:
>>> It's in next now, so please send follow-ups against sr/vcs-helper.
>>
>> Do you mean 'pu' or 'next'?
>
> Sorry, my hands did not type what my mind intended, I meant to say
> 'pu', apologies!

Fine---mistakes happen; it made me worried for a while.

So either follow-up, squash-in or replacement would be fine.