From patchwork Mon Dec 21 22:30:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Tan X-Patchwork-Id: 11985357 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 C75E0C433DB for ; Mon, 21 Dec 2020 22:32:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DEFE22B51 for ; Mon, 21 Dec 2020 22:32:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726117AbgLUWbs (ORCPT ); Mon, 21 Dec 2020 17:31:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725913AbgLUWbs (ORCPT ); Mon, 21 Dec 2020 17:31:48 -0500 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21DE0C0613D6 for ; Mon, 21 Dec 2020 14:31:08 -0800 (PST) Received: by mail-qv1-xf49.google.com with SMTP id t17so9090529qvv.17 for ; Mon, 21 Dec 2020 14:31:08 -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=fXiPqqkC5E+hnqWcgByCRhNq16K9MEBvbp1Q6N3JGXc=; b=MN77yVFtgJs9JX4myPCR8tjioUDKs6btAOIeFxfRtlvwBSxwnlKnvevlMs+8EmnCXN GA5dOvgo8mu6do4is9pY8MXciQg2hHHVfpqKq5A9oWfMFiiZVI2aZf7bURNuSfcaDIJQ uhFucTN9l1z7nyBxCEn00tC2ZtQzBkWdBjwKrTyZEH7ANBvPLeIjTeKejF/6Jjob7jLj 6I3RfW0iV5Q2Pz7jGn/Zm859nnPabQreGpviIhTwQsjgmvuANRfp1uekwT9wzryOB6CK 4p68q2cq43gMrH3yueoayzKjqRdr9Zl03TJEVa3OC+2eX9hm9o2/dZ7JiPO6xhGhj/e5 /2Ag== 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=fXiPqqkC5E+hnqWcgByCRhNq16K9MEBvbp1Q6N3JGXc=; b=P6TICFa0P0yEE1ukyh5aYRWVKPGmuvQ0y8kh9zIx1yqNxJSRNedh9FpAz4dmZxrEtF nzVQuEyRCQFRGoWXC2HYwO5BVs61iBmT+ShBfdt4Se0rGXMMPGO1WbUxEshMCFgCt20w kFO9Do8sWpY8ZouzqAV7Vl/7A6zH2RACDcpsZPXNcU4QyztlX6wiSKqQ5sZ6UU4CiMNP mmmuaCVlc27dpiBPN9McmtT5I7wjlKlRyatiC1OE3G3bxBCXDEMWvyKHAgzMVc/JLxo+ IzvHaZtZDAH80O1c+uQTJXuCn7XnMy+V0akGemdmfi4H1B3sFBvNE0fjhyWYZV9cI+OB 4nRA== X-Gm-Message-State: AOAM5339PKhcjqQAA1gJcHPk8pB/OTILItksgsY4/XhTeqJZiMD0Ul6G lhuQDYB1YNcMgIiAX4CgVB5ybc/4viB3h06jhGaOsSfT55ZxQ49fXgwDe+8Fec3yndMrlhFgW4N yBEODZwIaIoN7Ucj5WeiF0v8z/lIMX59KfJDudC7EcIsgPZZV0QSLz6OJbUN0+qqS06vYgzJOa4 W2 X-Google-Smtp-Source: ABdhPJx2ndbNbbGl+As6hvevqQ8qWWySWv4NE2NhqWdwZLokrxN5UpRkZ2k7cr05dU4/ppB1XmZkYtjz5IAEFLSnIX38 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:ad4:5192:: with SMTP id b18mr19422491qvp.46.1608589867283; Mon, 21 Dec 2020 14:31:07 -0800 (PST) Date: Mon, 21 Dec 2020 14:30:59 -0800 In-Reply-To: Message-Id: <7d20ec323a11e83fb8605abe4608a74a9b15373f.1608587839.git.jonathantanmy@google.com> Mime-Version: 1.0 References: <20201211210508.2337494-1-jonathantanmy@google.com> X-Mailer: git-send-email 2.29.2.729.g45daf8777d-goog Subject: [PATCH v3 1/3] ls-refs: report unborn targets of symrefs From: Jonathan Tan To: git@vger.kernel.org Cc: Jonathan Tan 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 | 51 +++++++++++++++++++++++-- ls-refs.h | 1 + serve.c | 2 +- 6 files changed, 63 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..82c79895c3 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 +79,29 @@ 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; + + 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 +117,7 @@ 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 +129,31 @@ 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 },