fetch-pack: unify ref in and out param

When a user fetches:
 - at least one up-to-date ref and at least one non-up-to-date ref,
 - using HTTP with protocol v0 (or something else that uses the fetch
   command of a remote helper)
some refs might not be updated after the fetch.

This bug was introduced in commit 989b8c4452 ("fetch-pack: put shallow
info in output parameter", 2018-06-28) which allowed transports to
report the refs that they have fetched in a new out-parameter
"fetched_refs". If they do so, transport_fetch_refs() makes this
information available to its caller.

Users of "fetched_refs" rely on the following 3 properties:
 (1) it is the complete list of refs that was passed to
     transport_fetch_refs(),
 (2) it has shallow information (REF_STATUS_REJECT_SHALLOW set if
     relevant), and
 (3) it has updated OIDs if ref-in-want was used (introduced after
     989b8c4452).

In an effort to satisfy (1), whenever transport_fetch_refs()
filters the refs sent to the transport, it re-adds the filtered refs to
whatever the transport supplies before returning it to the user.
However, the implementation in 989b8c4452 unconditionally re-adds the
filtered refs without checking if the transport refrained from reporting
anything in "fetched_refs" (which it is allowed to do), resulting in an
incomplete list, no longer satisfying (1).

An earlier effort to resolve this [1] solved the issue by readding the
filtered refs only if the transport did not refrain from reporting in
"fetched_refs", but after further discussion, it seems that the better
solution is to revert the API change that introduced "fetched_refs".
This API change was first suggested as part of a ref-in-want
implementation that allowed for ref patterns and, thus, there could be
drastic differences between the input refs and the refs actually fetched
[2]; we eventually decided to only allow exact ref names, but this API
change remained even though its necessity was decreased.

Therefore, revert this API change by reverting commit 989b8c4452, and
make receive_wanted_refs() update the OIDs in the sought array (like how
update_shallow() updates shallow information in the sought array)
instead. A test is also included to show that the user-visible bug
discussed at the beginning of this commit message no longer exists.

[1] https://public-inbox.org/git/20180801171806.GA122458@google.com/
[2] https://public-inbox.org/git/86a128c5fb710a41791e7183207c4d64889f9307.1485381677.git.jonathantanmy@google.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index 8f86d99c51f099805c752ba460cf99e6a77891b0..99e73dae8595d37f704d0fe7f7fd84a190edfcf6 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1155,7 +1155,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
                        }
 
                if (!is_local && !complete_refs_before_fetch)
-                       transport_fetch_refs(transport, mapped_refs, NULL);
+                       transport_fetch_refs(transport, mapped_refs);
 
                remote_head = find_ref_by_name(refs, "HEAD");
                remote_head_points_at =
@@ -1197,7 +1197,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
        if (is_local)
                clone_local(path, git_dir);
        else if (refs && complete_refs_before_fetch)
-               transport_fetch_refs(transport, mapped_refs, NULL);
+               transport_fetch_refs(transport, mapped_refs);
 
        update_remote_refs(refs, mapped_refs, remote_head_points_at,
                           branch_top.buf, reflog_msg.buf, transport,

diff --git a/builtin/fetch.c b/builtin/fetch.c
index d4b2767d488950d6ed4153d35d3af2cb2b677d7d..8f68ba8309e2cd30997d32009518666d0928de26 100644 (file)
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -948,13 +948,11 @@ static int quickfetch(struct ref *ref_map)
        return check_connected(iterate_ref_map, &rm, &opt);
 }
 
-static int fetch_refs(struct transport *transport, struct ref *ref_map,
-                     struct ref **updated_remote_refs)
+static int fetch_refs(struct transport *transport, struct ref *ref_map)
 {
        int ret = quickfetch(ref_map);
        if (ret)
-               ret = transport_fetch_refs(transport, ref_map,
-                                          updated_remote_refs);
+               ret = transport_fetch_refs(transport, ref_map);
        if (!ret)
                /*
                 * Keep the new pack's ".keep" file around to allow the caller
@@ -1119,7 +1117,7 @@ static void backfill_tags(struct transport *transport, struct ref *ref_map)
        transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
        transport_set_option(transport, TRANS_OPT_DEPTH, "0");
        transport_set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, NULL);
-       if (!fetch_refs(transport, ref_map, NULL))
+       if (!fetch_refs(transport, ref_map))
                consume_refs(transport, ref_map);
 
        if (gsecondary) {
@@ -1135,7 +1133,6 @@ static int do_fetch(struct transport *transport,
        int autotags = (transport->remote->fetch_tags == 1);
        int retcode = 0;
        const struct ref *remote_refs;
-       struct ref *updated_remote_refs = NULL;
        struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
        if (tags == TAGS_DEFAULT) {
@@ -1186,24 +1183,7 @@ static int do_fetch(struct transport *transport,
                                   transport->url);
                }
        }
-
-       if (fetch_refs(transport, ref_map, &updated_remote_refs)) {
-               free_refs(ref_map);
-               retcode = 1;
-               goto cleanup;
-       }
-       if (updated_remote_refs) {
-               /*
-                * Regenerate ref_map using the updated remote refs.  This is
-                * to account for additional information which may be provided
-                * by the transport (e.g. shallow info).
-                */
-               free_refs(ref_map);
-               ref_map = get_ref_map(transport->remote, updated_remote_refs, rs,
-                                     tags, &autotags);
-               free_refs(updated_remote_refs);
-       }
-       if (consume_refs(transport, ref_map)) {
+       if (fetch_refs(transport, ref_map) || consume_refs(transport, ref_map)) {
                free_refs(ref_map);
                retcode = 1;
                goto cleanup;

diff --git a/fetch-object.c b/fetch-object.c
index 48fe63dd6cf935d02724a0d862f43c070083bbf2..853624f811c59c17af88814ebeecf4154095a19c 100644 (file)
--- a/fetch-object.c
+++ b/fetch-object.c
@@ -19,7 +19,7 @@ static void fetch_refs(const char *remote_name, struct ref *ref)
 
        transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
        transport_set_option(transport, TRANS_OPT_NO_DEPENDENTS, "1");
-       transport_fetch_refs(transport, ref, NULL);
+       transport_fetch_refs(transport, ref);
        fetch_if_missing = original_fetch_if_missing;
 }
 

diff --git a/fetch-pack.c b/fetch-pack.c
index 60bbffb9764fa78896cbf994360f3ab407a9ce16..660259e6b2a875cd49208d7c01de0708c57a67a4 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1338,25 +1338,26 @@ static void receive_shallow_info(struct fetch_pack_args *args,
        args->deepen = 1;
 }
 
-static void receive_wanted_refs(struct packet_reader *reader, struct ref *refs)
+static void receive_wanted_refs(struct packet_reader *reader,
+                               struct ref **sought, int nr_sought)
 {
        process_section_header(reader, "wanted-refs", 0);
        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
                struct object_id oid;
                const char *end;
-               struct ref *r = NULL;
+               int i;
 
                if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
                        die("expected wanted-ref, got '%s'", reader->line);
 
-               for (r = refs; r; r = r->next) {
-                       if (!strcmp(end, r->name)) {
-                               oidcpy(&r->old_oid, &oid);
+               for (i = 0; i < nr_sought; i++) {
+                       if (!strcmp(end, sought[i]->name)) {
+                               oidcpy(&sought[i]->old_oid, &oid);
                                break;
                        }
                }
 
-               if (!r)
+               if (i == nr_sought)
                        die("unexpected wanted-ref: '%s'", reader->line);
        }
 
@@ -1439,7 +1440,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
                                receive_shallow_info(args, &reader);
 
                        if (process_section_header(&reader, "wanted-refs", 1))
-                               receive_wanted_refs(&reader, ref);
+                               receive_wanted_refs(&reader, sought, nr_sought);
 
                        /* get the pack */
                        process_section_header(&reader, "packfile", 0);
@@ -1503,13 +1504,12 @@ static int remove_duplicates_in_refs(struct ref **ref, int nr)
 }
 
 static void update_shallow(struct fetch_pack_args *args,
-                          struct ref *refs,
+                          struct ref **sought, int nr_sought,
                           struct shallow_info *si)
 {
        struct oid_array ref = OID_ARRAY_INIT;
        int *status;
        int i;
-       struct ref *r;
 
        if (args->deepen && alternate_shallow_file) {
                if (*alternate_shallow_file == '\0') { /* --unshallow */
@@ -1551,8 +1551,8 @@ static void update_shallow(struct fetch_pack_args *args,
        remove_nonexistent_theirs_shallow(si);
        if (!si->nr_ours && !si->nr_theirs)
                return;
-       for (r = refs; r; r = r->next)
-               oid_array_append(&ref, &r->old_oid);
+       for (i = 0; i < nr_sought; i++)
+               oid_array_append(&ref, &sought[i]->old_oid);
        si->ref = &ref;
 
        if (args->update_shallow) {
@@ -1586,12 +1586,12 @@ static void update_shallow(struct fetch_pack_args *args,
         * remote is also shallow, check what ref is safe to update
         * without updating .git/shallow
         */
-       status = xcalloc(ref.nr, sizeof(*status));
+       status = xcalloc(nr_sought, sizeof(*status));
        assign_shallow_commits_to_refs(si, NULL, status);
        if (si->nr_ours || si->nr_theirs) {
-               for (r = refs, i = 0; r; r = r->next, i++)
+               for (i = 0; i < nr_sought; i++)
                        if (status[i])
-                               r->status = REF_STATUS_REJECT_SHALLOW;
+                               sought[i]->status = REF_STATUS_REJECT_SHALLOW;
        }
        free(status);
        oid_array_clear(&ref);
@@ -1654,7 +1654,7 @@ struct ref *fetch_pack(struct fetch_pack_args *args,
                args->connectivity_checked = 1;
        }
 
-       update_shallow(args, ref_cpy, &si);
+       update_shallow(args, sought, nr_sought, &si);
 cleanup:
        clear_shallow_info(&si);
        return ref_cpy;

diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 913089b14452976144878415c05a9a2c743d22bf..989d034accba41e9fa4d13256642882bb75a7e3a 100755 (executable)
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -369,6 +369,24 @@ test_expect_success 'custom http headers' '
                submodule update sub
 '
 
+test_expect_success 'using fetch command in remote-curl updates refs' '
+       SERVER="$HTTPD_DOCUMENT_ROOT_PATH/twobranch" &&
+       rm -rf "$SERVER" client &&
+
+       git init "$SERVER" &&
+       test_commit -C "$SERVER" foo &&
+       git -C "$SERVER" update-ref refs/heads/anotherbranch foo &&
+
+       git clone $HTTPD_URL/smart/twobranch client &&
+
+       test_commit -C "$SERVER" bar &&
+       git -C client -c protocol.version=0 fetch &&
+
+       git -C "$SERVER" rev-parse master >expect &&
+       git -C client rev-parse origin/master >actual &&
+       test_cmp expect actual
+'
+
 test_expect_success 'GIT_REDACT_COOKIES redacts cookies' '
        rm -rf clone &&
        echo "Set-Cookie: Foo=1" >cookies &&

diff --git a/transport-helper.c b/transport-helper.c
index 8b5abca29f9492c03c234170ae1c66ba9f0970bb..1f8ff7e9424e5d780578a6ab00623f814d8f836a 100644 (file)
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -651,16 +651,14 @@ static int connect_helper(struct transport *transport, const char *name,
 }
 
 static int fetch(struct transport *transport,
-                int nr_heads, struct ref **to_fetch,
-                struct ref **fetched_refs)
+                int nr_heads, struct ref **to_fetch)
 {
        struct helper_data *data = transport->data;
        int i, count;
 
        if (process_connect(transport, 0)) {
                do_take_over(transport);
-               return transport->vtable->fetch(transport, nr_heads, to_fetch,
-                                               fetched_refs);
+               return transport->vtable->fetch(transport, nr_heads, to_fetch);
        }
 
        count = 0;

diff --git a/transport-internal.h b/transport-internal.h
index eeb6c340e51eab341b7f089bf2b425697759f3cd..1cde6258a73bcf8582b0746d1c44a23b30115dc9 100644 (file)
--- a/transport-internal.h
+++ b/transport-internal.h
@@ -36,18 +36,11 @@ struct transport_vtable {
         * Fetch the objects for the given refs. Note that this gets
         * an array, and should ignore the list structure.
         *
-        * The transport *may* provide, in fetched_refs, the list of refs that
-        * it fetched.  If the transport knows anything about the fetched refs
-        * that the caller does not know (for example, shallow status), it
-        * should provide that list of refs and include that information in the
-        * list.
-        *
         * 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,
-                    struct ref **fetched_refs);
+       int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
 
        /**
         * Push the objects and refs. Send the necessary objects, and

diff --git a/transport.c b/transport.c
index fdd813f684f766fe22169537468402677b0eaa71..af6e692db2a92f637ec6645c130dd3a8fcbd2dff 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -151,8 +151,7 @@ static struct ref *get_refs_from_bundle(struct transport *transport,
 }
 
 static int fetch_refs_from_bundle(struct transport *transport,
-                              int nr_heads, struct ref **to_fetch,
-                              struct ref **fetched_refs)
+                              int nr_heads, struct ref **to_fetch)
 {
        struct bundle_transport_data *data = transport->data;
        return unbundle(&data->header, data->fd,
@@ -288,8 +287,7 @@ 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, struct ref **to_fetch,
-                              struct ref **fetched_refs)
+                              int nr_heads, struct ref **to_fetch)
 {
        int ret = 0;
        struct git_transport_data *data = transport->data;
@@ -357,12 +355,8 @@ static int fetch_refs_via_pack(struct transport *transport,
        if (report_unmatched_refs(to_fetch, nr_heads))
                ret = -1;
 
-       if (fetched_refs)
-               *fetched_refs = refs;
-       else
-               free_refs(refs);
-
        free_refs(refs_tmp);
+       free_refs(refs);
        free(dest);
        return ret;
 }
@@ -1222,31 +1216,19 @@ const struct ref *transport_get_remote_refs(struct transport *transport,
        return transport->remote_refs;
 }
 
-int transport_fetch_refs(struct transport *transport, struct ref *refs,
-                        struct ref **fetched_refs)
+int transport_fetch_refs(struct transport *transport, struct ref *refs)
 {
        int rc;
        int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
        struct ref **heads = NULL;
-       struct ref *nop_head = NULL, **nop_tail = &nop_head;
        struct ref *rm;
 
        for (rm = refs; rm; rm = rm->next) {
                nr_refs++;
                if (rm->peer_ref &&
                    !is_null_oid(&rm->old_oid) &&
-                   !oidcmp(&rm->peer_ref->old_oid, &rm->old_oid)) {
-                       /*
-                        * These need to be reported as fetched, but we don't
-                        * actually need to fetch them.
-                        */
-                       if (fetched_refs) {
-                               struct ref *nop_ref = copy_ref(rm);
-                               *nop_tail = nop_ref;
-                               nop_tail = &nop_ref->next;
-                       }
+                   !oidcmp(&rm->peer_ref->old_oid, &rm->old_oid))
                        continue;
-               }
                ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
                heads[nr_heads++] = rm;
        }
@@ -1264,11 +1246,7 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs,
                        heads[nr_heads++] = rm;
        }
 
-       rc = transport->vtable->fetch(transport, nr_heads, heads, fetched_refs);
-       if (fetched_refs && nop_head) {
-               *nop_tail = *fetched_refs;
-               *fetched_refs = nop_head;
-       }
+       rc = transport->vtable->fetch(transport, nr_heads, heads);
 
        free(heads);
        return rc;

diff --git a/transport.h b/transport.h
index 7a9a7fcaf3ebf4afcd4d181d54de7e0791451fc7..c057c44d358739c3e319034f8886e7e8867773f3 100644 (file)
--- a/transport.h
+++ b/transport.h
@@ -229,8 +229,7 @@ int transport_push(struct transport *connection,
 const struct ref *transport_get_remote_refs(struct transport *transport,
                                            const struct argv_array *ref_prefixes);
 
-int transport_fetch_refs(struct transport *transport, struct ref *refs,
-                        struct ref **fetched_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);