From: Justin Tobler Date: Wed, 23 Jul 2025 19:00:10 GMT Subject: Re: [PATCH 4/8] builtin/reflog: implement subcommand to write new entries Message-ID: In-Reply-To: <20250722-pks-reflog-append-v1-4-183e5949de16@pks.im> On 25/07/22 01:20PM, Patrick Steinhardt wrote: > While we provide a couple of subcommands in git-reflog(1) to remove > reflog entries, we don't provide any to write new entries. Obviously > this is not an operation that really would be needed for many use cases > out there, or otherwise people would have complained that such a command > does not exist yet. But the introduction of the "reftable" backend > changes the picture a bit, as it is now basically impossible to manually > append a reflog entry if one wanted to do so due to the binary format. > > Plug this gap by introducing a simple "write" subcommand. For now, all > this command does is to append a single new reflog entry with the given > object IDs and message to the reflog. More specifically, it is not yet > possible to: > > - Write multiple reflog entries at once. > > - Insert reflog entries at arbitrary indices. > > - Specify the date of the reflog entry. > > - Insert reflog entries that refer to nonexistent objects. > > If required, those features can be added at a future point in time. For > now though, the new command aims to fulfill the most basic use cases > while being as strict as possible when it comes to verifying parameters. > > Signed-off-by: Patrick Steinhardt > --- > Documentation/git-reflog.adoc | 1 + > builtin/reflog.c | 65 ++++++++++++++++++++++++++++++++++ > t/meson.build | 1 + > t/t1421-reflog-write.sh | 81 +++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 148 insertions(+) > > diff --git a/Documentation/git-reflog.adoc b/Documentation/git-reflog.adoc > index 6ae13e772b8..798dbc0a00a 100644 > --- a/Documentation/git-reflog.adoc > +++ b/Documentation/git-reflog.adoc > @@ -12,6 +12,7 @@ SYNOPSIS > git reflog [show] [] [] > git reflog list > git reflog exists > +git reflog write The other subcommands each have an entry in the description. Do we want to also add something for the "write" subcommand? Also, if we want to be consistent, I noticed the order of the subcommands listed in the description was not changed either. > git reflog delete [--rewrite] [--updateref] > [--dry-run | -n] [--verbose] @{}... > git reflog drop [--all [--single-worktree] | ...] > diff --git a/builtin/reflog.c b/builtin/reflog.c > index b00b3f9edc9..d0374295620 100644 > --- a/builtin/reflog.c > +++ b/builtin/reflog.c > @@ -3,6 +3,8 @@ > #include "builtin.h" > #include "config.h" > #include "gettext.h" > +#include "hex.h" > +#include "odb.h" > #include "revision.h" > #include "reachable.h" > #include "wildmatch.h" > @@ -20,6 +22,9 @@ > #define BUILTIN_REFLOG_EXISTS_USAGE \ > N_("git reflog exists ") > > +#define BUILTIN_REFLOG_WRITE_USAGE \ > + N_("git reflog write ") > + > #define BUILTIN_REFLOG_DELETE_USAGE \ > N_("git reflog delete [--rewrite] [--updateref]\n" \ > " [--dry-run | -n] [--verbose] @{}...") > @@ -47,6 +52,11 @@ static const char *const reflog_exists_usage[] = { > NULL, > }; > > +static const char *const reflog_write_usage[] = { > + BUILTIN_REFLOG_WRITE_USAGE, > + NULL, > +}; > + > static const char *const reflog_delete_usage[] = { > BUILTIN_REFLOG_DELETE_USAGE, > NULL > @@ -66,6 +76,7 @@ static const char *const reflog_usage[] = { > BUILTIN_REFLOG_SHOW_USAGE, > BUILTIN_REFLOG_LIST_USAGE, > BUILTIN_REFLOG_EXISTS_USAGE, > + BUILTIN_REFLOG_WRITE_USAGE, > BUILTIN_REFLOG_DELETE_USAGE, > BUILTIN_REFLOG_DROP_USAGE, > BUILTIN_REFLOG_EXPIRE_USAGE, > @@ -392,6 +403,59 @@ static int cmd_reflog_drop(int argc, const char **argv, const char *prefix, > return ret; > } > > +static int cmd_reflog_write(int argc, const char **argv, const char *prefix, > + struct repository *repo) > +{ > + const struct option options[] = { > + OPT_END() > + }; > + struct object_id old_oid, new_oid; > + struct strbuf err = STRBUF_INIT; > + struct ref_transaction *tx; > + const char *ref, *message; > + int ret; > + > + argc = parse_options(argc, argv, prefix, options, reflog_drop_usage, 0); > + if (argc != 4) > + usage_with_options(reflog_write_usage, options); > + > + ref = argv[0]; > + if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL)) > + die(_("invalid reference name: %s"), ref); > + > + ret = get_oid_hex_algop(argv[1], &old_oid, repo->hash_algo); > + if (ret) > + die(_("invalid old object ID: '%s'"), argv[1]); > + if (!is_null_oid(&old_oid) && !odb_has_object(repo->objects, &old_oid, 0)) > + die(_("old object '%s' does not exist"), argv[1]); > + > + ret = get_oid_hex_algop(argv[2], &new_oid, repo->hash_algo); > + if (ret) > + die(_("invalid new object ID: '%s'"), argv[2]); > + if (!is_null_oid(&new_oid) && !odb_has_object(repo->objects, &new_oid, 0)) > + die(_("new object '%s' does not exist"), argv[2]); Ok so we validate the reference name and the old/new obects names to make sure they are sane. > + > + message = argv[3]; > + > + tx = ref_store_transaction_begin(get_main_ref_store(repo), 0, &err); > + if (!tx) > + die(_("cannot start transaction: %s"), err.buf); > + > + ret = ref_transaction_update_reflog(tx, ref, &new_oid, &old_oid, > + git_committer_info(0), > + message, 0, &err); > + if (ret) > + die(_("cannot queue reflog update: %s"), err.buf); > + > + ret = ref_transaction_commit(tx, &err); > + if (ret) > + die(_("cannot commit reflog update: %s"), err.buf); And here we write the reflog entry. Looks good > + > + ref_transaction_free(tx); > + strbuf_release(&err); > + return 0; > +} > + > /* > * main "reflog" > */ > @@ -405,6 +469,7 @@ int cmd_reflog(int argc, > OPT_SUBCOMMAND("show", &fn, cmd_reflog_show), > OPT_SUBCOMMAND("list", &fn, cmd_reflog_list), > OPT_SUBCOMMAND("exists", &fn, cmd_reflog_exists), > + OPT_SUBCOMMAND("write", &fn, cmd_reflog_write), > OPT_SUBCOMMAND("delete", &fn, cmd_reflog_delete), > OPT_SUBCOMMAND("drop", &fn, cmd_reflog_drop), > OPT_SUBCOMMAND("expire", &fn, cmd_reflog_expire), > diff --git a/t/meson.build b/t/meson.build > index 1af289425d4..d68f5e24dbe 100644 > --- a/t/meson.build > +++ b/t/meson.build > @@ -219,6 +219,7 @@ integration_tests = [ > 't1418-reflog-exists.sh', > 't1419-exclude-refs.sh', > 't1420-lost-found.sh', > + 't1421-reflog-write.sh', > 't1430-bad-ref-name.sh', > 't1450-fsck.sh', > 't1451-fsck-buffer.sh', > diff --git a/t/t1421-reflog-write.sh b/t/t1421-reflog-write.sh > new file mode 100755 > index 00000000000..e284f42178f > --- /dev/null > +++ b/t/t1421-reflog-write.sh > @@ -0,0 +1,81 @@ > +#!/bin/sh > + > +test_description='Manually write reflog entries' > + > +. ./test-lib.sh > + > +SIGNATURE="C O Mitter 1112911993 -0700" > + > +test_reflog_matches () { > + repo="$1" && > + refname="$2" && > + cat >actual && > + test-tool -C "$repo" ref-store main for-each-reflog-ent "$refname" >expected && > + test_cmp expected actual > +} > + > +test_expect_success 'invalid number of arguments' ' > + test_when_finished "rm -rf repo" && > + git init repo && > + ( > + cd repo && > + for args in "" "1" "1 2" "1 2 3" "1 2 3 4 5" > + do > + test_must_fail git reflog write $args 2>err && > + test_grep "usage: git reflog write" err || return 1 > + done > + ) > +' > + > +test_expect_success 'invalid refname' ' > + test_when_finished "rm -rf repo" && > + git init repo && > + ( > + cd repo && > + test_must_fail git reflog write "refs/heads/ invalid" $ZERO_OID $ZERO_OID first 2>err && > + test_grep "invalid reference name: " err > + ) > +' > + > +test_expect_success 'nonexistent old object ID' ' > + test_when_finished "rm -rf repo" && > + git init repo && > + ( > + cd repo && > + test_must_fail git reflog write refs/heads/something $(test_oid deadbeef) $ZERO_OID first 2>err && > + test_grep "old object .* does not exist" err > + ) > +' > + > +test_expect_success 'nonexistent new object ID' ' > + test_when_finished "rm -rf repo" && > + git init repo && > + ( > + cd repo && > + test_must_fail git reflog write refs/heads/something $ZERO_OID $(test_oid deadbeef) first 2>err && > + test_grep "new object .* does not exist" err > + ) > +' > + > +test_expect_success 'simple writes' ' > + test_when_finished "rm -rf repo" && > + git init repo && > + ( > + cd repo && > + test_commit initial && > + COMMIT_OID=$(git rev-parse HEAD) && > + > + git reflog write refs/heads/something $ZERO_OID $COMMIT_OID first && > + test_reflog_matches . refs/heads/something <<-EOF && > + $ZERO_OID $COMMIT_OID $SIGNATURE first > + EOF > + > + git reflog write refs/heads/something $COMMIT_OID $COMMIT_OID second && > + test_reflog_matches . refs/heads/something <<-EOF > + $ZERO_OID $COMMIT_OID $SIGNATURE first > + $COMMIT_OID $COMMIT_OID $SIGNATURE second > + EOF > + ) > +' > + > +test_done > > -- > 2.50.1.465.gcb3da1c9e6.dirty > >