@matheusbsbs / matheus-bagliano / commits / 6ab4055775

transport: list refs before fetch if necessary

The built-in bundle transport and the transport helper interface do not work when transport_fetch_refs() is called immediately after transport creation. This will be needed in a subsequent patch, so fix this. Evidence: fetch_refs_from_bundle() relies on data->header being initialized in get_refs_from_bundle(), and fetch() in transport-helper.c relies on either data->fetch or data->import being set by get_helper(), but neither transport_helper_init() nor fetch() calls get_helper(). Up until the introduction of the partial clone feature, this has not been a problem, because transport_fetch_refs() is always called after transport_get_remote_refs(). With the introduction of the partial clone feature, which involves calling transport_fetch_refs() (to fetch objects by their OIDs) without transport_get_remote_refs(), this is still not a problem, but only coincidentally - we do not support partially cloning a bundle, and as for cloning using a transport-helper-using protocol, it so happens that before transport_fetch_refs() is called, fetch_refs() in fetch-object.c calls transport_set_option(), which means that the aforementioned get_helper() is invoked through set_helper_option() in transport-helper.c. This could be fixed by fixing the transports themselves, but it doesn't seem like a good idea to me to open up previously untested code paths; also, there may be transport helpers in the wild that assume that "list" is always called before "fetch". Instead, fix this by having transport_fetch_refs() call transport_get_remote_refs() to ensure that the latter is always called at least once, unless the transport explicitly states that it supports fetching without listing refs. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jonathan Tan committed Sep 27, 2018 at 12:24 UTC 6ab4055775b0e560d1f2a1be2e7251d872874655

3 files changed +19

transport-helper.c

@@ -1105,6 +1105,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push,

1105 }

1106

1107 static struct transport_vtable vtable = {

1108 + 0,

1109 set_helper_option,

1110 get_refs_list,

1111 fetch,

transport-internal.h

@@ -6,6 +6,12 @@ struct transport;

6 struct argv_array;

8 struct transport_vtable {

9 + /**

10 + * This transport supports the fetch() function being called

11 + * without get_refs_list() first being called.

12 + */

13 + unsigned fetch_without_list : 1;

14 +

15 /**

16 * Returns 0 if successful, positive if the option is not

17 * recognized or is inapplicable, and negative if the option

transport.c

+12

@@ -733,6 +733,7 @@ static int disconnect_git(struct transport *transport)

733 }

734

735 static struct transport_vtable taken_over_vtable = {

736 + 1,

737 NULL,

738 get_refs_via_connect,

739 fetch_refs_via_pack,

@@ -882,6 +883,7 @@ void transport_check_allowed(const char *type)

883 }

884

885 static struct transport_vtable bundle_vtable = {

886 + 0,

887 NULL,

888 get_refs_from_bundle,

889 fetch_refs_from_bundle,

@@ -891,6 +893,7 @@ static struct transport_vtable bundle_vtable = {

893 };

894

895 static struct transport_vtable builtin_smart_vtable = {

896 + 1,

897 NULL,

898 get_refs_via_connect,

899 fetch_refs_via_pack,

@@ -1254,6 +1257,15 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs)

1257 struct ref **heads = NULL;

1258 struct ref *rm;

1259

1260 + if (!transport->vtable->fetch_without_list)

1261 + /*

1262 + * Some transports (e.g. the built-in bundle transport and the

1263 + * transport helper interface) do not work when fetching is

1264 + * done immediately after transport creation. List the remote

1265 + * refs anyway (if not already listed) as a workaround.

1266 + */

1267 + transport_get_remote_refs(transport, NULL);

1268 +

1269 for (rm = refs; rm; rm = rm->next) {

1270 nr_refs++;

1271 if (rm->peer_ref &&