From patchwork Mon May 13 22:41:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Junio C Hamano X-Patchwork-Id: 13663703 Received: from pb-smtp1.pobox.com (pb-smtp1.pobox.com [64.147.108.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEE7C84E08 for ; Mon, 13 May 2024 22:41:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=64.147.108.70 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715640102; cv=none; b=c+mwEv6zeTzVeQkIHpzHetiKkZOnsdnSLdGERPdVrk7muzP/XusYAfu7sV6Swwp1H4h0acXxR7TXQkKOrkoPZP+g1SBABQwvTm6eiK7L1WMZ6ueDF+r3Q2NZRdr9fL0AGhwOjEOWQG2sTRbNzE40FwbAVRXEjETe226NmL2XvVM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715640102; c=relaxed/simple; bh=JcwZt4AJ/mrDbdPEul+myS3c9zWuBRZ0hpgULWJKYgY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ej1jpxEaOCaJ73XNaZODxtJgoIoH5bfh4k7szMizt4l6RdAyKwaFibTuYNtGQJhDemTvrn29fJs37tSsgeT1zTPD9ftKrnDygTR9cO7jaPWjf9dYpujMvwEEFis7ojggNX0263lodniRj57fbbOgUJc+eIhIQGOJzJlQhCVp7iQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com; spf=pass smtp.mailfrom=pobox.com; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b=iiDApNIK; arc=none smtp.client-ip=64.147.108.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pobox.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b="iiDApNIK" Received: from pb-smtp1.pobox.com (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id 80A1137082; Mon, 13 May 2024 18:41:39 -0400 (EDT) (envelope-from gitster@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; s=sasl; bh=JcwZt4AJ/mrD bdPEul+myS3c9zWuBRZ0hpgULWJKYgY=; b=iiDApNIKvzUE+Xty5/oksEVwkj1Y 87L34XCGvl5F0V2pP6A3kFhQ95X13By74j/hamrxd277ICoAhQFx7ZwREeWIVDAS znv8I7Bu4XybD0XTbVNiypBwgRng6cyUVpD6O/LXNGnrQ8OcfZOoP2YNKwUidRa9 ICCMxc7JY9BQ6Yw= Received: from pb-smtp1.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id 7954D37081; Mon, 13 May 2024 18:41:39 -0400 (EDT) (envelope-from gitster@pobox.com) Received: from pobox.com (unknown [34.125.153.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp1.pobox.com (Postfix) with ESMTPSA id DF73C37080; Mon, 13 May 2024 18:41:38 -0400 (EDT) (envelope-from gitster@pobox.com) From: Junio C Hamano To: git@vger.kernel.org Cc: Patrick Steinhardt Subject: [PATCH v3 3/5] builtin/patch-id: fix uninitialized hash function Date: Mon, 13 May 2024 15:41:25 -0700 Message-ID: <20240513224127.2042052-4-gitster@pobox.com> X-Mailer: git-send-email 2.45.0-145-g3e4a232f6e In-Reply-To: <20240513224127.2042052-1-gitster@pobox.com> References: <20240513224127.2042052-1-gitster@pobox.com> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Pobox-Relay-ID: F618C686-1179-11EF-BF83-78DCEB2EC81B-77302942!pb-smtp1.pobox.com From: Patrick Steinhardt In c8aed5e8da (repository: stop setting SHA1 as the default object hash, 2024-05-07), we have adapted `initialize_repository()` to no longer set up a default hash function. As this function is also used to set up `the_repository`, the consequence is that `the_hash_algo` will now by default be a `NULL` pointer unless the hash algorithm was configured properly. This is done as a mechanism to detect cases where we may be using the wrong hash function by accident. This change now causes git-patch-id(1) to segfault when it's run outside of a repository. As this command can read diffs from stdin, it does not necessarily need a repository, but then relies on `the_hash_algo` to compute the patch ID itself. It is somewhat dubious that git-patch-id(1) relies on `the_hash_algo` in the first place. Quoting its manpage: A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a patch, with line numbers ignored. As such, it’s "reasonably stable", but at the same time also reasonably unique, i.e., two patches that have the same "patch ID" are almost guaranteed to be the same thing. We explicitly document patch IDs to be using SHA-1. Furthermore, patch IDs are supposed to be stable for most of the part. But even with the same input, the patch IDs will now be different depending on the repo's configured object hash. Work around the issue by setting up SHA-1 when there was no startup repository for now. This is arguably not the correct fix, but for now we rather want to focus on getting the segfault fixed. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/patch-id.c | 13 +++++++++++++ t/t1517-outside-repo.sh | 2 +- t/t4204-patch-id.sh | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 1 deletion(-) diff --git a/builtin/patch-id.c b/builtin/patch-id.c index 3894d2b970..e6ae89beab 100644 --- a/builtin/patch-id.c +++ b/builtin/patch-id.c @@ -5,6 +5,7 @@ #include "hash.h" #include "hex.h" #include "parse-options.h" +#include "setup.h" static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result) { @@ -237,6 +238,18 @@ int cmd_patch_id(int argc, const char **argv, const char *prefix) argc = parse_options(argc, argv, prefix, builtin_patch_id_options, patch_id_usage, 0); + /* + * We rely on `the_hash_algo` to compute patch IDs. This is dubious as + * it means that the hash algorithm now depends on the object hash of + * the repository, even though git-patch-id(1) clearly defines that + * patch IDs always use SHA1. + * + * NEEDSWORK: This hack should be removed in favor of converting + * the code that computes patch IDs to always use SHA1. + */ + if (!startup_info->have_repository) + repo_set_hash_algo(the_repository, GIT_HASH_SHA1); + generate_id_list(opts ? opts > 1 : config.stable, opts ? opts == 3 : config.verbatim); return 0; diff --git a/t/t1517-outside-repo.sh b/t/t1517-outside-repo.sh index 16d9714c27..f1fd5c9888 100755 --- a/t/t1517-outside-repo.sh +++ b/t/t1517-outside-repo.sh @@ -24,7 +24,7 @@ test_expect_success 'set up a non-repo directory and test file' ' git diff >sample.patch ' -test_expect_failure 'compute a patch-id outside repository' ' +test_expect_success 'compute a patch-id outside repository' ' git patch-id patch-id.expect && ( cd non-repo && diff --git a/t/t4204-patch-id.sh b/t/t4204-patch-id.sh index a7fa94ce0a..605faea0c7 100755 --- a/t/t4204-patch-id.sh +++ b/t/t4204-patch-id.sh @@ -310,4 +310,38 @@ test_expect_success 'patch-id handles diffs with one line of before/after' ' test_config patchid.stable true && calc_patch_id diffu1stable diff <<-\EOF && + diff --git a/bar b/bar + index bdaf90f..31051f6 100644 + --- a/bar + +++ b/bar + @@ -2 +2,2 @@ + b + +c + EOF + + git init --object-format=sha1 repo-sha1 && + git -C repo-sha1 patch-id patch-id-sha1 && + git init --object-format=sha256 repo-sha256 && + git -C repo-sha256 patch-id patch-id-sha256 && + test_cmp patch-id-sha1 patch-id-sha256 +' + +test_expect_success 'patch-id without repository' ' + cat >diff <<-\EOF && + diff --git a/bar b/bar + index bdaf90f..31051f6 100644 + --- a/bar + +++ b/bar + @@ -2 +2,2 @@ + b + +c + EOF + nongit git patch-id