From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Nieder Subject: [PATCH 15/24] branch -d: avoid repeated symref resolution Date: Wed, 1 Oct 2014 19:15:10 -0700 Message-ID: <20141002021510.GH1175@google.com> References: <20140820231723.GF20185@google.com> <20140911030318.GD18279@google.com> <20141002014817.GS1175@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "git@vger.kernel.org" , Michael Haggerty To: Ronnie Sahlberg X-From: git-owner@vger.kernel.org Thu Oct 02 04:15:21 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XZVvM-00041T-Bz for gcvg-git-2@plane.gmane.org; Thu, 02 Oct 2014 04:15:20 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751341AbaJBCPO (ORCPT ); Wed, 1 Oct 2014 22:15:14 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:38477 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750868AbaJBCPN (ORCPT ); Wed, 1 Oct 2014 22:15:13 -0400 Received: by mail-pa0-f45.google.com with SMTP id rd3so1363910pab.32 for ; Wed, 01 Oct 2014 19:15:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=VryjpdHSvv2DHQWO2M5livBiMWRMUl904ciUeIywQAU=; b=E0AK8AhPwtCvc1MLra2ivX6FxjU4ycKSarCcKtVFSQecibAo4BxecxmAZexQm2n9FS p/HWBSSmoLnD1iN2eDYm8rOerd2vNN2cUau2UYtpHmfBfAbOYN4AQMjJxwZAp6CbgVbO x0DSGn9l4Ni75VKkjm0gTQXxSERGj9beCkKFh4A8VgcCL+ykyAXNaT4m7OtKP1fjVceC jF5NbQzn1TAIolpSCxUwHUgx9NttK+YqRLCKKKKYk/KDMcwiGpk15QeP9JgU+GQbBMhv mRJb20QBvjEl7UPe5QCXf3SU+hC9AhX6cNRbbEvj22tFHyVTu62L/UNN9/8f42l098T2 Ph8Q== X-Received: by 10.66.151.196 with SMTP id us4mr80360024pab.78.1412216112920; Wed, 01 Oct 2014 19:15:12 -0700 (PDT) Received: from google.com (aiede.mtv.corp.google.com [172.27.69.120]) by mx.google.com with ESMTPSA id y5sm2179850pdl.6.2014.10.01.19.15.11 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 01 Oct 2014 19:15:12 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20141002014817.GS1175@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: From: Jonathan Nieder Date: Wed, 10 Sep 2014 18:22:48 -0700 If a repository gets in a broken state with too much symref nesting, it cannot be repaired with "git branch -d": $ git symbolic-ref refs/heads/nonsense refs/heads/nonsense $ git branch -d nonsense error: branch 'nonsense' not found. Worse, "git update-ref --no-deref -d" doesn't work for such repairs either: $ git update-ref -d refs/heads/nonsense error: unable to resolve reference refs/heads/nonsense: Too many levels of symbolic links Fix both by teaching resolve_ref_unsafe a new RESOLVE_REF_NO_RECURSE flag and passing it when appropriate. Callers can still read the value of a symref (for example to print a message about it) with that flag set --- resolve_ref_unsafe will resolve one level of symrefs and stop there. Signed-off-by: Jonathan Nieder Reviewed-by: Ronnie Sahlberg --- Since v21: - renamed flag from RESOLVE_REF_NO_DEREF to _NO_RECURSE - more detail in API docs - only set NO_RECURSE when deleting refs. Locking refs for non-deletion updates needs to recurse to get old_sha1 for the reflog. - add more tests (for symrefs to refs with bad names, which should also be deletable now) builtin/branch.c | 3 ++- cache.h | 6 ++++++ refs.c | 17 +++++++++++++++-- refs.h | 2 ++ t/t1400-update-ref.sh | 34 ++++++++++++++++++++++++++++++++++ t/t3200-branch.sh | 9 +++++++++ 6 files changed, 68 insertions(+), 3 deletions(-) diff --git a/builtin/branch.c b/builtin/branch.c index e5d1377..a334380 100644 --- a/builtin/branch.c +++ b/builtin/branch.c @@ -234,7 +234,8 @@ static int delete_branches(int argc, const char **argv, int force, int kinds, free(name); name = mkpathdup(fmt, bname.buf); - target = resolve_ref_unsafe(name, 0, sha1, &flags); + target = resolve_ref_unsafe(name, RESOLVE_REF_NO_RECURSE, + sha1, &flags); if (!target || (!(flags & REF_ISSYMREF) && is_null_sha1(sha1))) { error(remote_branch diff --git a/cache.h b/cache.h index 5b54911..5ca7f2b 100644 --- a/cache.h +++ b/cache.h @@ -970,6 +970,11 @@ extern int read_ref(const char *refname, unsigned char *sha1); * "writing" to the ref, the return value is the name of the ref * that will actually be created or changed. * + * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one + * level of symbolic reference. The value stored in sha1 for a symbolic + * reference will always be null_sha1 in this case, and the return + * value is the reference that the symref refers to directly. + * * If flags is non-NULL, set the value that it points to the * combination of REF_ISPACKED (if the reference was found among the * packed references), REF_ISSYMREF (if the initial reference was a @@ -982,6 +987,7 @@ extern int read_ref(const char *refname, unsigned char *sha1); * errno is set to something meaningful on error. */ #define RESOLVE_REF_READING 0x01 +#define RESOLVE_REF_NO_RECURSE 0x02 extern const char *resolve_ref_unsafe(const char *ref, int resolve_flags, unsigned char *sha1, int *flags); extern char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags); diff --git a/refs.c b/refs.c index 4916d16..490e788 100644 --- a/refs.c +++ b/refs.c @@ -1407,6 +1407,10 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned refname = refname_buffer; if (flags) *flags |= REF_ISSYMREF; + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } continue; } } @@ -1463,13 +1467,17 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned buf = buffer + 4; while (isspace(*buf)) buf++; + refname = strcpy(refname_buffer, buf); + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { if (flags) *flags |= REF_ISBROKEN; errno = EINVAL; return NULL; } - refname = strcpy(refname_buffer, buf); } } @@ -2111,6 +2119,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, if (mustexist) resolve_flags |= RESOLVE_REF_READING; + if (flags & REF_NODEREF && flags & REF_DELETING) + resolve_flags |= RESOLVE_REF_NO_RECURSE; refname = resolve_ref_unsafe(refname, resolve_flags, lock->old_sha1, &type); @@ -3610,13 +3620,16 @@ int ref_transaction_commit(struct ref_transaction *transaction, /* Acquire all locks while verifying old values */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; + int flags = update->flags; + if (is_null_sha1(update->new_sha1)) + flags |= REF_DELETING; update->lock = lock_ref_sha1_basic(update->refname, (update->have_old ? update->old_sha1 : NULL), NULL, - update->flags, + flags, &update->type); if (!update->lock) { ret = (errno == ENOTDIR) diff --git a/refs.h b/refs.h index 3bb16db..b62c4c4 100644 --- a/refs.h +++ b/refs.h @@ -175,10 +175,12 @@ extern int peel_ref(const char *refname, unsigned char *sha1); * ref_transaction_create(), etc. * REF_NODEREF: act on the ref directly, instead of dereferencing * symbolic references. + * REF_DELETING: tolerate broken refs * * Flags >= 0x100 are reserved for internal use. */ #define REF_NODEREF 0x01 +#define REF_DELETING 0x02 /* * This function sets errno to something meaningful on failure. */ diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh index 0218e96..7c8c41a 100755 --- a/t/t1400-update-ref.sh +++ b/t/t1400-update-ref.sh @@ -110,6 +110,40 @@ test_expect_success "delete symref without dereference when the referred ref is cp -f .git/HEAD.orig .git/HEAD git update-ref -d $m +test_expect_success 'update-ref -d is not confused by self-reference' ' + git symbolic-ref refs/heads/self refs/heads/self && + test_when_finished "rm -f .git/refs/heads/self" && + test_path_is_file .git/refs/heads/self && + test_must_fail git update-ref -d refs/heads/self && + test_path_is_file .git/refs/heads/self +' + +test_expect_success 'update-ref --no-deref -d can delete self-reference' ' + git symbolic-ref refs/heads/self refs/heads/self && + test_when_finished "rm -f .git/refs/heads/self" && + test_path_is_file .git/refs/heads/self && + git update-ref --no-deref -d refs/heads/self && + test_path_is_missing .git/refs/heads/self +' + +test_expect_success 'update-ref --no-deref -d can delete reference to bad ref' ' + >.git/refs/heads/bad && + test_when_finished "rm -f .git/refs/heads/bad" && + git symbolic-ref refs/heads/ref-to-bad refs/heads/bad && + test_when_finished "rm -f .git/refs/heads/ref-to-bad" && + test_path_is_file .git/refs/heads/ref-to-bad && + git update-ref --no-deref -d refs/heads/ref-to-bad && + test_path_is_missing .git/refs/heads/ref-to-bad +' + +test_expect_success 'update-ref --no-deref -d can delete reference to broken name' ' + git symbolic-ref refs/heads/badname refs/heads/broken...ref && + test_when_finished "rm -f .git/refs/heads/badname" && + test_path_is_file .git/refs/heads/badname && + git update-ref --no-deref -d refs/heads/badname && + test_path_is_missing .git/refs/heads/badname +' + test_expect_success '(not) create HEAD with old sha1' " test_must_fail git update-ref HEAD $A $B " diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh index ac31b71..432921b 100755 --- a/t/t3200-branch.sh +++ b/t/t3200-branch.sh @@ -285,6 +285,15 @@ test_expect_success 'deleting a dangling symref' ' test_i18ncmp expect actual ' +test_expect_success 'deleting a self-referential symref' ' + git symbolic-ref refs/heads/self-reference refs/heads/self-reference && + test_path_is_file .git/refs/heads/self-reference && + echo "Deleted branch self-reference (was refs/heads/self-reference)." >expect && + git branch -d self-reference >actual && + test_path_is_missing .git/refs/heads/self-reference && + test_i18ncmp expect actual +' + test_expect_success 'renaming a symref is not allowed' ' git symbolic-ref refs/heads/master2 refs/heads/master && test_must_fail git branch -m master2 master3 && -- 2.1.0.rc2.206.gedb03e5