[PATCH v4 4/7] push.c: add an --atomic-push argument

[Stefan Beller <sbeller@google.com>]

From: Ronnie Sahlberg <sahlberg@google.com>

Add a command line argument to the git push command to request atomic
pushes.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 Documentation/git-push.txt | 7 ++++++-
 builtin/push.c             | 2 ++
 transport.c                | 1 +
 transport.h                | 1 +
 4 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
index 21b3f29..04de8d8 100644
--- a/Documentation/git-push.txt
+++ b/Documentation/git-push.txt
@@ -9,7 +9,7 @@ git-push - Update remote refs along with associated objects
 SYNOPSIS
 --------
 [verse]
-'git push' [--all | --mirror | --tags] [--follow-tags] [-n | --dry-run] [--receive-pack=<git-receive-pack>]
+'git push' [--all | --mirror | --tags] [--follow-tags] [--atomic-push] [-n | --dry-run] [--receive-pack=<git-receive-pack>]
 	   [--repo=<repository>] [-f | --force] [--prune] [-v | --verbose]
 	   [-u | --set-upstream] [--signed]
 	   [--force-with-lease[=<refname>[:<expect>]]]
@@ -136,6 +136,11 @@ already exists on the remote side.
 	logged.  See linkgit:git-receive-pack[1] for the details
 	on the receiving end.
 
+--atomic-push::
+	Try using atomic push. If atomic push is negotiated with the server
+	then any push covering multiple refs will be atomic. Either all
+	refs are updated, or on error, no refs are updated.
+
 --receive-pack=<git-receive-pack>::
 --exec=<git-receive-pack>::
 	Path to the 'git-receive-pack' program on the remote
diff --git a/builtin/push.c b/builtin/push.c
index a076b19..ae393c5 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -518,6 +518,8 @@ int cmd_push(int argc, const char **argv, const char *prefix)
 		OPT_BIT(0, "follow-tags", &flags, N_("push missing but relevant tags"),
 			TRANSPORT_PUSH_FOLLOW_TAGS),
 		OPT_BIT(0, "signed", &flags, N_("GPG sign the push"), TRANSPORT_PUSH_CERT),
+		OPT_BIT(0, "atomic-push", &flags, N_("use atomic push, if available"),
+			TRANSPORT_ATOMIC_PUSH),
 		OPT_END()
 	};
 
diff --git a/transport.c b/transport.c
index 2111986..cd2b63a 100644
--- a/transport.c
+++ b/transport.c
@@ -833,6 +833,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
 	args.porcelain = !!(flags & TRANSPORT_PUSH_PORCELAIN);
 	args.push_cert = !!(flags & TRANSPORT_PUSH_CERT);
+	args.use_atomic_push = !!(flags & TRANSPORT_ATOMIC_PUSH);
 	args.url = transport->url;
 
 	ret = send_pack(&args, data->fd, data->conn, remote_refs,
diff --git a/transport.h b/transport.h
index 3e0091e..25fa1da 100644
--- a/transport.h
+++ b/transport.h
@@ -125,6 +125,7 @@ struct transport {
 #define TRANSPORT_PUSH_NO_HOOK 512
 #define TRANSPORT_PUSH_FOLLOW_TAGS 1024
 #define TRANSPORT_PUSH_CERT 2048
+#define TRANSPORT_ATOMIC_PUSH 4096
 
 #define TRANSPORT_SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
 #define TRANSPORT_SUMMARY(x) (int)(TRANSPORT_SUMMARY_WIDTH + strlen(x) - gettext_width(x)), (x)
-- 
2.2.0.rc2.5.gf7b9fb2