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![Jonathan Tan](/assets/img/avatar_default.png)
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 commit989b8c4452
("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 after989b8c4452
). 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 in989b8c4452
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 commit989b8c4452
, 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>
71 lines
2.6 KiB
C
71 lines
2.6 KiB
C
#ifndef TRANSPORT_INTERNAL_H
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#define TRANSPORT_INTERNAL_H
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struct ref;
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struct transport;
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struct argv_array;
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struct transport_vtable {
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/**
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* Returns 0 if successful, positive if the option is not
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* recognized or is inapplicable, and negative if the option
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* is applicable but the value is invalid.
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**/
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int (*set_option)(struct transport *connection, const char *name,
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const char *value);
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/**
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* Returns a list of the remote side's refs. In order to allow
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* the transport to try to share connections, for_push is a
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* hint as to whether the ultimate operation is a push or a fetch.
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*
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* If communicating using protocol v2 a list of prefixes can be
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* provided to be sent to the server to enable it to limit the ref
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* advertisement. Since ref filtering is done on the server's end, and
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* only when using protocol v2, this list will be ignored when not
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* using protocol v2 meaning this function can return refs which don't
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* match the provided ref_prefixes.
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*
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* If the transport is able to determine the remote hash for
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* the ref without a huge amount of effort, it should store it
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* in the ref's old_sha1 field; otherwise it should be all 0.
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**/
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struct ref *(*get_refs_list)(struct transport *transport, int for_push,
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const struct argv_array *ref_prefixes);
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/**
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* Fetch the objects for the given refs. Note that this gets
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* an array, and should ignore the list structure.
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*
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* If the transport did not get hashes for refs in
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* get_refs_list(), it should set the old_sha1 fields in the
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* provided refs now.
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**/
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int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
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/**
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* Push the objects and refs. Send the necessary objects, and
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* then, for any refs where peer_ref is set and
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* peer_ref->new_oid is different from old_oid, tell the
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* remote side to update each ref in the list from old_oid to
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* peer_ref->new_oid.
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*
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* Where possible, set the status for each ref appropriately.
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*
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* The transport must modify new_sha1 in the ref to the new
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* value if the remote accepted the change. Note that this
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* could be a different value from peer_ref->new_oid if the
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* process involved generating new commits.
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**/
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int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
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int (*connect)(struct transport *connection, const char *name,
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const char *executable, int fd[2]);
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/** get_refs_list(), fetch(), and push_refs() can keep
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* resources (such as a connection) reserved for further
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* use. disconnect() releases these resources.
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**/
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int (*disconnect)(struct transport *connection);
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};
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#endif
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