Add a check to verify if the remote-tracking ref of the local branch
is reachable from one of its "reflog" entries.
When a local branch that is based on a remote ref, has been rewound
and is to be force pushed on the remote, "--force-if-includes" runs
a check that ensures any updates to remote-tracking refs that may have
happened (by push from another repository) in-between the time of the
last checkout, and right before the time of push, have been integrated
locally before allowing a forced updated.
A new field "use_force_if_includes" has been added to "push_cas_option",
which is set to "1" when "--force-if-includes" is specified as an
option in the command line or as a configuration setting.
The struct "ref" has two new bit-fields:
- check_reachable:
Set when we have to run the new check on the ref, and the remote
ref was marked as "use_tracking" or "use_tracking_for_rest" by
compare-and-swap (if the "the remote tip must be at the expected
commit" condition is not specified); "apply_push_cas()" has been
updated to check if this field is set and run the check.
- unreachable:
Set if the ref is unreachable from any of the "reflog" entries of
its local counterpart.
"REF_STATUS_REJECT_REMOTE_UPDATED" has been added to the "status"
enum to imply that the ref failed the check; "case" statements in
"send-pack", "transport" and "transport-helper" have been updated
accordingly to catch this status when set.
When "--force-is-includes" is used along with "--force-with-lease",
the check runs only for refs marked as "if_includes". If the option
is passed without specifying "--force-with-lease", or specified along
with "--force-with-lease=<refname>:<expect>" it is a "no-op".
Signed-off-by: Srinidhi Kaushik <shrinidhi.kaushik@xxxxxxxxx>
---
builtin/send-pack.c | 5 ++
remote.c | 140 +++++++++++++++++++++++++++++++++++++++++++-
remote.h | 8 ++-
send-pack.c | 1 +
transport-helper.c | 5 ++
transport.c | 6 ++
6 files changed, 162 insertions(+), 3 deletions(-)
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 2b9610f121..4d76727edb 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -69,6 +69,11 @@ static void print_helper_status(struct ref *ref)
msg = "stale info";
break;
+ case REF_STATUS_REJECT_REMOTE_UPDATED:
+ res = "error";
+ msg = "remote ref updated since checkout";
+ break;
+
case REF_STATUS_REJECT_ALREADY_EXISTS:
res = "error";
msg = "already exists";
diff --git a/remote.c b/remote.c
index eafc14cbe7..0dcac4ab8e 100644
--- a/remote.c
+++ b/remote.c
@@ -1471,12 +1471,23 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
* with the remote-tracking branch to find the value
* to expect, but we did not have such a tracking
* branch.
+ *
+ * If the tip of the remote-tracking ref is unreachable
+ * from any reflog entry of its local ref indicating a
+ * possible update since checkout; reject the push.
*/
if (ref->expect_old_sha1) {
if (!oideq(&ref->old_oid, &ref->old_oid_expect))
reject_reason = REF_STATUS_REJECT_STALE;
+ else if (ref->check_reachable && ref->unreachable)
+ reject_reason =
+ REF_STATUS_REJECT_REMOTE_UPDATED;
else
- /* If the ref isn't stale then force the update. */
+ /*
+ * If the ref isn't stale, and is reachable
+ * from from one of the reflog entries of
+ * the local branch, force the update.
+ */
force_ref_update = 1;
}
@@ -2268,6 +2279,118 @@ static int remote_tracking(struct remote *remote, const char *refname,
return 0;
}
+/*
+ * The struct "reflog_commit_list" and related helper functions
+ * for list manipulation are used for collecting commits into a
+ * list during reflog traversals in "if_exists_or_grab_until()".
+ */
+struct reflog_commit_list {
+ struct commit **items;
+ size_t nr, alloc;
+};
+
+/* Adds a commit to list. */
+static void add_commit(struct reflog_commit_list *list, struct commit *commit)
+{
+ ALLOC_GROW(list->items, list->nr + 1, list->alloc);
+ list->items[list->nr++] = commit;
+}
+
+/* Free and reset the list. */
+static void free_reflog_commit_list(struct reflog_commit_list *list)
+{
+ FREE_AND_NULL(list->items);
+ list->nr = list->alloc = 0;
+}
+
+struct check_and_collect_until_cb_data {
+ struct commit *remote_commit;
+ struct reflog_commit_list *local_commits;
+};
+
+
+static int check_and_collect_until(struct object_id *o_oid,
+ struct object_id *n_oid,
+ const char *ident, timestamp_t timestamp,
+ int tz, const char *message, void *cb_data)
+{
+ struct commit *commit;
+ struct check_and_collect_until_cb_data *cb = cb_data;
+
+ /*
+ * If the reflog entry timestamp is older than the
+ * remote commit date, there is no need to check or
+ * collect entries older than this one.
+ */
+ if (timestamp < cb->remote_commit->date)
+ return -1;
+
+ /* An entry was found. */
+ if (oideq(n_oid, &cb->remote_commit->object.oid))
+ return 1;
+
+ /* Lookup the commit and append it to the list. */
+ if ((commit = lookup_commit_reference(the_repository, n_oid)))
+ add_commit(cb->local_commits, commit);
+
+ return 0;
+}
+
+/*
+ * Iterate through the reflog of a local ref to check if there is an entry for
+ * the given remote-tracking ref (i.e., if it was checked out); runs until the
+ * timestamp of an entry is older than the commit date of the remote-tracking
+ * ref. Any commits that seen along the way are collected into a list to check
+ * if the remote-tracking ref is reachable from any of them.
+ */
+static int is_reachable_in_reflog(const char *local_ref_name,
+ const struct object_id *remote_oid)
+{
+ struct commit *remote_commit;
+ struct reflog_commit_list list = { NULL, 0, 0 };
+ struct check_and_collect_until_cb_data cb;
+ int ret = 0;
+
+ remote_commit = lookup_commit_reference(the_repository, remote_oid);
+ if (!remote_commit)
+ goto cleanup_return;
+
+ cb.remote_commit = remote_commit;
+ cb.local_commits = &list;
+ ret = for_each_reflog_ent_reverse(local_ref_name,
+ check_and_collect_until, &cb);
+
+ /* We found an entry in the reflog. */
+ if (ret > 0)
+ goto cleanup_return;
+
+ /*
+ * Check if "remote_commit" is reachable from
+ * any of the commits in the collected list.
+ */
+ if (list.nr > 0)
+ ret = in_merge_bases_many(remote_commit, list.nr, list.items);
+
+cleanup_return:
+ free_reflog_commit_list(&list);
+ return ret;
+}
+
+/*
+ * Check for reachability of a remote-tracking
+ * ref in the reflog entries of its local ref.
+ */
+static void check_if_includes_upstream(struct ref *remote_ref)
+{
+ struct ref *local_ref = get_local_ref(remote_ref->name);
+
+ if (!local_ref)
+ return;
+
+ if (!is_reachable_in_reflog(local_ref->name, &remote_ref->old_oid))
+ remote_ref->unreachable = 1;
+}
+
static void apply_cas(struct push_cas_option *cas,
struct remote *remote,
struct ref *ref)
@@ -2284,6 +2407,8 @@ static void apply_cas(struct push_cas_option *cas,
oidcpy(&ref->old_oid_expect, &entry->expect);
else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
oidclr(&ref->old_oid_expect);
+ else
+ ref->check_reachable = cas->use_force_if_includes;
return;
}
@@ -2294,6 +2419,8 @@ static void apply_cas(struct push_cas_option *cas,
ref->expect_old_sha1 = 1;
if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
oidclr(&ref->old_oid_expect);
+ else
+ ref->check_reachable = cas->use_force_if_includes;
}
void apply_push_cas(struct push_cas_option *cas,
@@ -2301,6 +2428,15 @@ void apply_push_cas(struct push_cas_option *cas,
struct ref *remote_refs)
{
struct ref *ref;
- for (ref = remote_refs; ref; ref = ref->next)
+ for (ref = remote_refs; ref; ref = ref->next) {
apply_cas(cas, remote, ref);
+
+ /*
+ * If "compare-and-swap" is in "use_tracking[_for_rest]"
+ * mode, and if "--force-if-includes" was specified, run
+ * the check.
+ */
+ if (ref->check_reachable)
+ check_if_includes_upstream(ref);
+ }
}
diff --git a/remote.h b/remote.h
index 5e3ea5a26d..7c5e59770e 100644
--- a/remote.h
+++ b/remote.h
@@ -104,7 +104,11 @@ struct ref {
forced_update:1,
expect_old_sha1:1,
exact_oid:1,
- deletion:1;
+ deletion:1,
+ /* Need to check if local reflog reaches the remote tip. */
+ check_reachable:1,
+ /* The local reflog does not reach the remote tip. */
+ unreachable:1;
enum {
REF_NOT_MATCHED = 0, /* initial value */
@@ -134,6 +138,7 @@ struct ref {
REF_STATUS_REJECT_NEEDS_FORCE,
REF_STATUS_REJECT_STALE,
REF_STATUS_REJECT_SHALLOW,
+ REF_STATUS_REJECT_REMOTE_UPDATED,
REF_STATUS_UPTODATE,
REF_STATUS_REMOTE_REJECT,
REF_STATUS_EXPECTING_REPORT,
@@ -332,6 +337,7 @@ struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map);
struct push_cas_option {
unsigned use_tracking_for_rest:1;
+ unsigned use_force_if_includes:1;
struct push_cas {
struct object_id expect;
unsigned use_tracking:1;
diff --git a/send-pack.c b/send-pack.c
index 632f1580ca..956306e8e8 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -240,6 +240,7 @@ static int check_to_send_update(const struct ref *ref, const struct send_pack_ar
case REF_STATUS_REJECT_FETCH_FIRST:
case REF_STATUS_REJECT_NEEDS_FORCE:
case REF_STATUS_REJECT_STALE:
+ case REF_STATUS_REJECT_REMOTE_UPDATED:
case REF_STATUS_REJECT_NODELETE:
return CHECK_REF_STATUS_REJECTED;
case REF_STATUS_UPTODATE:
diff --git a/transport-helper.c b/transport-helper.c
index c52c99d829..e547e21199 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -779,6 +779,10 @@ static int push_update_ref_status(struct strbuf *buf,
status = REF_STATUS_REJECT_STALE;
FREE_AND_NULL(msg);
}
+ else if (!strcmp(msg, "remote ref updated since checkout")) {
+ status = REF_STATUS_REJECT_REMOTE_UPDATED;
+ FREE_AND_NULL(msg);
+ }
else if (!strcmp(msg, "forced update")) {
forced = 1;
FREE_AND_NULL(msg);
@@ -897,6 +901,7 @@ static int push_refs_with_push(struct transport *transport,
case REF_STATUS_REJECT_NONFASTFORWARD:
case REF_STATUS_REJECT_STALE:
case REF_STATUS_REJECT_ALREADY_EXISTS:
+ case REF_STATUS_REJECT_REMOTE_UPDATED:
if (atomic) {
reject_atomic_push(remote_refs, mirror);
string_list_clear(&cas_options, 0);
diff --git a/transport.c b/transport.c
index 43e24bf1e5..99fe6233a3 100644
--- a/transport.c
+++ b/transport.c
@@ -567,6 +567,11 @@ static int print_one_push_status(struct ref *ref, const char *dest, int count,
print_ref_status('!', "[rejected]", ref, ref->peer_ref,
"stale info", porcelain, summary_width);
break;
+ case REF_STATUS_REJECT_REMOTE_UPDATED:
+ print_ref_status('!', "[rejected]", ref, ref->peer_ref,
+ "remote ref updated since checkout",
+ porcelain, summary_width);
+ break;
case REF_STATUS_REJECT_SHALLOW:
print_ref_status('!', "[rejected]", ref, ref->peer_ref,
"new shallow roots not allowed",
@@ -1101,6 +1106,7 @@ static int run_pre_push_hook(struct transport *transport,
if (!r->peer_ref) continue;
if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) continue;
if (r->status == REF_STATUS_REJECT_STALE) continue;
+ if (r->status == REF_STATUS_REJECT_REMOTE_UPDATED) continue;
if (r->status == REF_STATUS_UPTODATE) continue;
strbuf_reset(&buf);
--
2.28.0
