From patchwork Tue Dec 22 21:54:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 11987343 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDBFEC433DB for ; Tue, 22 Dec 2020 21:55:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A810622AAE for ; Tue, 22 Dec 2020 21:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727094AbgLVVzG (ORCPT ); Tue, 22 Dec 2020 16:55:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726617AbgLVVzG (ORCPT ); Tue, 22 Dec 2020 16:55:06 -0500 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D2F9C0613D6 for ; Tue, 22 Dec 2020 13:54:26 -0800 (PST) Received: by mail-pf1-x44a.google.com with SMTP id n8so7468567pfa.8 for ; Tue, 22 Dec 2020 13:54:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=x+ysT12046PncuVlKdg2i4QsPJbCQVLg7MKol3Qzdh8=; b=rxU7vZLDl8/FBpxyEIoqUhY7BDCubMf45UvPfwwaR0A6YGBCXcqj7jBACXP+deqbDW tm4kzlpThww5RAvj774zQ/oFmo8ewbMJbkiN/hU617uo11Ajc65D7YHT1XX9qDUemL60 GbuR5LqB8/jqHcLT1FWU9KggI5tQws0mD9dJUmpGszTL4yhuwaw4iPydMBLY2iO5RSeN 9LT3uvdksypoMPct90WMT6j2a0yr61nH5Ca8OE3FR7u8G6h2gYn7+mR2H6qP0M/AIDRu Ct9e7cx79S/5XWRzTwgpU9Dhp+briLXVYI3E33+kWell8x++6gK4C/0b2NTwLzScwf6h ioLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=x+ysT12046PncuVlKdg2i4QsPJbCQVLg7MKol3Qzdh8=; b=jsx6D24KF6RnwFd2xuLZ0t7KNDgyCfJn5E5xqDqrgfoRsZKlBxn83vaelu2Necbqfv Hx58E6lAiUz/+MCM3KTEFMeZHIX9Uuk9ovFFWKK08OhAFNYjFZEqW2s1i1RTMD98QiY3 3dkHfXjo4h0QwLZNi7CnTreM1rjuvj3Kv46ZWULZjei3KCLsij7asgwokIITRdPh6Pwh i8ROV94d/4QI04V7c5Ea2gICUXhkoj8bIVSlWJvgjXDy0xVKi6txXke+rf4czVUaTDEQ ujgc0rXdVoUQLuQibbNR0LfJblQMKpGfMLm2bvWZSQksRleg9sJ49vlVQGO1CYb9hkgh 5Y7w== X-Gm-Message-State: AOAM533DDh/Xw0fJahkCLuXrBVlg98KWSqXrx6iktTjB2xTKJ6BafzGw jSV99t2JlMH12RogTN3ijjpQYkwiSev/HW+e3KFSzQDSERs4BRPbZX1E+inZrruEevI5hA0O5kU plTQP2SqqfHIeneFzLuutAz85IDR2vTF5jVboCJgdXooCuCdMTUt6fQ2NG/dGTMBhKasmGJYNYY xP X-Google-Smtp-Source: ABdhPJyH914HTD9qZRJOMNeKLYBUDzrrgVyb/lCGUW+C35BhexcRnWDRkpOg2H5YlVGHo+FD3YYdtXDui/Lp1Mo2EhxX Sender: "jonathantanmy via sendgmr" X-Received: from twelve4.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:437a]) (user=jonathantanmy job=sendgmr) by 2002:a17:902:9309:b029:db:c725:d19c with SMTP id bc9-20020a1709029309b02900dbc725d19cmr1178571plb.39.1608674065570; Tue, 22 Dec 2020 13:54:25 -0800 (PST) Date: Tue, 22 Dec 2020 13:54:18 -0800 In-Reply-To: Message-Id: Mime-Version: 1.0 References: <20201211210508.2337494-1-jonathantanmy@google.com> X-Mailer: git-send-email 2.29.2.729.g45daf8777d-goog Subject: [PATCH v4 1/3] ls-refs: report unborn targets of symrefs From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan , gitster@pobox.com Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org When cloning, we choose the default branch based on the remote HEAD. But if there is no remote HEAD reported (which could happen if the target of the remote HEAD is unborn), we'll fall back to using our local init.defaultBranch. Traditionally this hasn't been a big deal, because most repos used "master" as the default. But these days it is likely to cause confusion if the server and client implementations choose different values (e.g., if the remote started with "main", we may choose "master" locally, create commits there, and then the user is surprised when they push to "master" and not "main"). To solve this, the remote needs to communicate the target of the HEAD symref, even if it is unborn, and "git clone" needs to use this information. Currently, symrefs that have unborn targets (such as in this case) are not communicated by the protocol. Teach Git to advertise and support the "unborn" feature in "ls-refs" (guarded by the lsrefs.allowunborn config). This feature indicates that "ls-refs" supports the "unborn" argument; when it is specified, "ls-refs" will send the HEAD symref with the name of its unborn target. This change is only for protocol v2. A similar change for protocol v0 would require independent protocol design (there being no analogous position to signal support for "unborn") and client-side plumbing of the data required, so the scope of this patch set is limited to protocol v2. The client side will be updated to use this in a subsequent commit. Signed-off-by: Jonathan Tan --- Documentation/config.txt | 2 + Documentation/config/lsrefs.txt | 3 ++ Documentation/technical/protocol-v2.txt | 10 ++++- ls-refs.c | 52 +++++++++++++++++++++++-- ls-refs.h | 1 + serve.c | 2 +- 6 files changed, 64 insertions(+), 6 deletions(-) create mode 100644 Documentation/config/lsrefs.txt diff --git a/Documentation/config.txt b/Documentation/config.txt index 6ba50b1104..d08e83a148 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -398,6 +398,8 @@ include::config/interactive.txt[] include::config/log.txt[] +include::config/lsrefs.txt[] + include::config/mailinfo.txt[] include::config/mailmap.txt[] diff --git a/Documentation/config/lsrefs.txt b/Documentation/config/lsrefs.txt new file mode 100644 index 0000000000..dcbec11aaa --- /dev/null +++ b/Documentation/config/lsrefs.txt @@ -0,0 +1,3 @@ +lsrefs.allowUnborn:: + Allow the server to send information about unborn symrefs during the + protocol v2 ref advertisement. diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt index 85daeb5d9e..4707511c10 100644 --- a/Documentation/technical/protocol-v2.txt +++ b/Documentation/technical/protocol-v2.txt @@ -192,11 +192,19 @@ ls-refs takes in the following arguments: When specified, only references having a prefix matching one of the provided prefixes are displayed. +If the 'unborn' feature is advertised the following argument can be +included in the client's request. + + unborn + The server may send symrefs pointing to unborn branches in the form + "unborn symref-target:". + The output of ls-refs is as follows: output = *ref flush-pkt - ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF) + obj-id-or-unborn = (obj-id | "unborn") + ref = PKT-LINE(obj-id-or-unborn SP refname *(SP ref-attribute) LF) ref-attribute = (symref | peeled) symref = "symref-target:" symref-target peeled = "peeled:" obj-id diff --git a/ls-refs.c b/ls-refs.c index a1e0b473e4..ff61e704f1 100644 --- a/ls-refs.c +++ b/ls-refs.c @@ -32,6 +32,8 @@ struct ls_refs_data { unsigned peel; unsigned symrefs; struct strvec prefixes; + unsigned allow_unborn : 1; + unsigned unborn : 1; }; static int send_ref(const char *refname, const struct object_id *oid, @@ -47,7 +49,10 @@ static int send_ref(const char *refname, const struct object_id *oid, if (!ref_match(&data->prefixes, refname_nons)) return 0; - strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons); + if (oid) + strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons); + else + strbuf_addf(&refline, "unborn %s", refname_nons); if (data->symrefs && flag & REF_ISSYMREF) { struct object_id unused; const char *symref_target = resolve_ref_unsafe(refname, 0, @@ -74,8 +79,30 @@ static int send_ref(const char *refname, const struct object_id *oid, return 0; } -static int ls_refs_config(const char *var, const char *value, void *data) +static void send_possibly_unborn_head(struct ls_refs_data *data) { + struct strbuf namespaced = STRBUF_INIT; + struct object_id oid; + int flag; + int oid_is_null; + + memset(&oid, 0, sizeof(oid)); + strbuf_addf(&namespaced, "%sHEAD", get_git_namespace()); + resolve_ref_unsafe(namespaced.buf, 0, &oid, &flag); + oid_is_null = is_null_oid(&oid); + if (!oid_is_null || + (data->unborn && data->symrefs && (flag & REF_ISSYMREF))) + send_ref(namespaced.buf, oid_is_null ? NULL : &oid, flag, data); + strbuf_release(&namespaced); +} + +static int ls_refs_config(const char *var, const char *value, void *cb_data) +{ + struct ls_refs_data *data = cb_data; + + if (!strcmp("lsrefs.allowunborn", var)) + data->allow_unborn = git_config_bool(var, value); + /* * We only serve fetches over v2 for now, so respect only "uploadpack" * config. This may need to eventually be expanded to "receive", but we @@ -91,7 +118,7 @@ int ls_refs(struct repository *r, struct strvec *keys, memset(&data, 0, sizeof(data)); - git_config(ls_refs_config, NULL); + git_config(ls_refs_config, &data); while (packet_reader_read(request) == PACKET_READ_NORMAL) { const char *arg = request->line; @@ -103,14 +130,31 @@ int ls_refs(struct repository *r, struct strvec *keys, data.symrefs = 1; else if (skip_prefix(arg, "ref-prefix ", &out)) strvec_push(&data.prefixes, out); + else if (data.allow_unborn && !strcmp("unborn", arg)) + data.unborn = 1; } if (request->status != PACKET_READ_FLUSH) die(_("expected flush after ls-refs arguments")); - head_ref_namespaced(send_ref, &data); + send_possibly_unborn_head(&data); for_each_namespaced_ref(send_ref, &data); packet_flush(1); strvec_clear(&data.prefixes); return 0; } + +int ls_refs_advertise(struct repository *r, struct strbuf *value) +{ + if (value) { + int allow_unborn_value; + + if (!repo_config_get_bool(the_repository, + "lsrefs.allowunborn", + &allow_unborn_value) && + allow_unborn_value) + strbuf_addstr(value, "unborn"); + } + + return 1; +} diff --git a/ls-refs.h b/ls-refs.h index 7b33a7c6b8..a99e4be0bd 100644 --- a/ls-refs.h +++ b/ls-refs.h @@ -6,5 +6,6 @@ struct strvec; struct packet_reader; int ls_refs(struct repository *r, struct strvec *keys, struct packet_reader *request); +int ls_refs_advertise(struct repository *r, struct strbuf *value); #endif /* LS_REFS_H */ diff --git a/serve.c b/serve.c index eec2fe6f29..ac20c72763 100644 --- a/serve.c +++ b/serve.c @@ -73,7 +73,7 @@ struct protocol_capability { static struct protocol_capability capabilities[] = { { "agent", agent_advertise, NULL }, - { "ls-refs", always_advertise, ls_refs }, + { "ls-refs", ls_refs_advertise, ls_refs }, { "fetch", upload_pack_advertise, upload_pack_v2 }, { "server-option", always_advertise, NULL }, { "object-format", object_format_advertise, NULL },