From: Li Chen <chenl311@xxxxxxxxxxxxxxx>
Implement a new `--trailer <text>` option for `git rebase`
(support merge backend only now), which appends arbitrary
trailer lines to each rebased commit message. Reject early
if used with the apply backend (git am) since it lacks
message‑filter/trailer hook. Automatically set REBASE_FORCE when
any trailer is supplied.
And reject invalid input before user edit the interactive file,
as suggested by Phillip Wood.
Signed-off-by: Li Chen <chenl311@xxxxxxxxxxxxxxx>
---
Documentation/git-rebase.adoc | 7 +++
builtin/rebase.c | 98 +++++++++++++++++++++++++++++++++++
sequencer.c | 13 +++++
sequencer.h | 3 ++
t/meson.build | 1 +
t/t3440-rebase-trailer.sh | 95 +++++++++++++++++++++++++++++++++
6 files changed, 217 insertions(+)
create mode 100755 t/t3440-rebase-trailer.sh
diff --git a/Documentation/git-rebase.adoc b/Documentation/git-rebase.adoc
index 956d3048f5..df8fb97526 100644
--- a/Documentation/git-rebase.adoc
+++ b/Documentation/git-rebase.adoc
@@ -521,6 +521,13 @@ See also INCOMPATIBLE OPTIONS below.
that if `--interactive` is given then only commits marked to be
picked, edited or reworded will have the trailer added.
+
+--trailer <trailer>::
+ Append the given trailer line(s) to every rebased commit
+ message, processed via linkgit:git-interpret-trailers[1].
+ When this option is present *rebase automatically enables*
+ `--force-rebase` so that fast‑forwarded commits are also
+ rewritten.
+
See also INCOMPATIBLE OPTIONS below.
-i::
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 2e8c4ee678..1e21caace7 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -36,6 +36,8 @@
#include "reset.h"
#include "trace2.h"
#include "hook.h"
+#include "trailer.h"
+#include "parse-options.h"
static char const * const builtin_rebase_usage[] = {
N_("git rebase [-i] [options] [--exec <cmd>] "
@@ -113,6 +115,7 @@ struct rebase_options {
enum action action;
char *reflog_action;
int signoff;
+ struct strvec trailer_args;
int allow_rerere_autoupdate;
int keep_empty;
int autosquash;
@@ -143,6 +146,7 @@ struct rebase_options {
.flags = REBASE_NO_QUIET, \
.git_am_opts = STRVEC_INIT, \
.exec = STRING_LIST_INIT_NODUP, \
+ .trailer_args = STRVEC_INIT, \
.git_format_patch_opt = STRBUF_INIT, \
.fork_point = -1, \
.reapply_cherry_picks = -1, \
@@ -166,6 +170,7 @@ static void rebase_options_release(struct rebase_options *opts)
free(opts->strategy);
string_list_clear(&opts->strategy_opts, 0);
strbuf_release(&opts->git_format_patch_opt);
+ strvec_clear(&opts->trailer_args);
}
static struct replay_opts get_replay_opts(const struct rebase_options *opts)
@@ -177,6 +182,10 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
sequencer_init_config(&replay);
replay.signoff = opts->signoff;
+
+ for (size_t i = 0; i < opts->trailer_args.nr; i++)
+ strvec_push(&replay.trailer_args, opts->trailer_args.v[i]);
+
replay.allow_ff = !(opts->flags & REBASE_FORCE);
if (opts->allow_rerere_autoupdate)
replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
@@ -435,6 +444,8 @@ static int read_basic_state(struct rebase_options *opts)
struct strbuf head_name = STRBUF_INIT;
struct strbuf buf = STRBUF_INIT;
struct object_id oid;
+ const char trailer_state_name[] = "trailer";
+ const char *path = state_dir_path(trailer_state_name, opts);
if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
READ_ONELINER_WARN_MISSING) ||
@@ -503,11 +514,31 @@ static int read_basic_state(struct rebase_options *opts)
strbuf_release(&buf);
+ if (strbuf_read_file(&buf, path, 0) >= 0) {
+ const char *p = buf.buf, *end = buf.buf + buf.len;
+
+ while (p < end) {
+ char *nl = memchr(p, '\n', end - p);
+ if (!nl)
+ die("nl shouldn't be NULL");
+ *nl = '\0';
+
+ if (*p)
+ strvec_push(&opts->trailer_args, p);
+
+ p = nl + 1;
+ }
+ strbuf_release(&buf);
+ }
+ strbuf_release(&buf);
+
return 0;
}
static int rebase_write_basic_state(struct rebase_options *opts)
{
+ const char trailer_state_name[] = "trailer";
+
write_file(state_dir_path("head-name", opts), "%s",
opts->head_name ? opts->head_name : "detached HEAD");
write_file(state_dir_path("onto", opts), "%s",
@@ -529,6 +560,22 @@ static int rebase_write_basic_state(struct rebase_options *opts)
if (opts->signoff)
write_file(state_dir_path("signoff", opts), "--signoff");
+ /*
+ * save opts->trailer_args into state_dir/trailer
+ */
+ if (opts->trailer_args.nr) {
+ struct strbuf buf = STRBUF_INIT;
+ size_t i;
+
+ for (i = 0; i < opts->trailer_args.nr; i++) {
+ strbuf_addstr(&buf, opts->trailer_args.v[i]);
+ strbuf_addch(&buf, '\n');
+ }
+ write_file(state_dir_path(trailer_state_name, opts),
+ "%s", buf.buf);
+ strbuf_release(&buf);
+ }
+
return 0;
}
@@ -1085,6 +1132,37 @@ static int check_exec_cmd(const char *cmd)
return 0;
}
+static int validate_trailer_args_after_config(const struct strvec *cli_args,
+ struct strbuf *err)
+{
+ size_t i;
+
+ for (i = 0; i < cli_args->nr; i++) {
+ const char *raw = cli_args->v[i];
+ const char *txt; // Key[:=]Val
+ const char *sep;
+
+ if (!skip_prefix(raw, "--trailer=", &txt))
+ txt = raw;
+
+ if (!*txt) {
+ strbuf_addstr(err, _("empty --trailer argument"));
+ return -1;
+ }
+
+ sep = strpbrk(txt, ":=");
+
+ /* there must be key bfore seperator */
+ if (sep && sep == txt) {
+ strbuf_addf(err,
+ _("invalid trailer '%s': missing key before separator"),
+ txt);
+ return -1;
+ }
+ }
+ return 0;
+}
+
int cmd_rebase(int argc,
const char **argv,
const char *prefix,
@@ -1132,6 +1210,7 @@ int cmd_rebase(int argc,
.flags = PARSE_OPT_NOARG,
.defval = REBASE_DIFFSTAT,
},
+ OPT_STRVEC(0, "trailer", &options.trailer_args, N_("trailer"), N_("add custom trailer(s)")),
OPT_BOOL(0, "signoff", &options.signoff,
N_("add a Signed-off-by trailer to each commit")),
OPT_BOOL(0, "committer-date-is-author-date",
@@ -1282,6 +1361,17 @@ int cmd_rebase(int argc,
builtin_rebase_options,
builtin_rebase_usage, 0);
+ /* if add --trailer，force rebase */
+ if (options.trailer_args.nr) {
+ struct strbuf err = STRBUF_INIT;
+
+ if (validate_trailer_args_after_config(&options.trailer_args, &err))
+ die("%s", err.buf);
+
+ options.flags |= REBASE_FORCE;
+ strbuf_release(&err);
+ }
+
if (preserve_merges_selected)
die(_("--preserve-merges was replaced by --rebase-merges\n"
"Note: Your `pull.rebase` configuration may also be set to 'preserve',\n"
@@ -1539,6 +1629,14 @@ int cmd_rebase(int argc,
if (options.root && !options.onto_name)
imply_merge(&options, "--root without --onto");
+ /*
+ * The apply‑based backend (git am) cannot append trailers because
+ * it lacks a message‑filter facility. Reject early, before any
+ * state (index, HEAD, etc.) is modified.
+ */
+ if (options.trailer_args.nr)
+ imply_merge(&options, "--trailer");
+
if (isatty(2) && options.flags & REBASE_NO_QUIET)
strbuf_addstr(&options.git_format_patch_opt, " --progress");
diff --git a/sequencer.c b/sequencer.c
index 1ee0abbd45..504642e4c7 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -422,6 +422,7 @@ void replay_opts_release(struct replay_opts *opts)
free(opts->revs);
replay_ctx_release(ctx);
free(opts->ctx);
+ strvec_clear(&opts->trailer_args);
}
int sequencer_remove_state(struct replay_opts *opts)
@@ -2527,6 +2528,18 @@ static int do_pick_commit(struct repository *r,
_("dropping %s %s -- patch contents already upstream\n"),
oid_to_hex(&commit->object.oid), msg.subject);
} /* else allow == 0 and there's nothing special to do */
+
+ if (!res && opts->trailer_args.nr && !drop_commit) {
+ const char *trailer_file =
+ msg_file ? msg_file : git_path_merge_msg(r);
+
+ if (amend_file_with_trailers(trailer_file,
+ &opts->trailer_args)) {
+ res = error(_("unable to add trailers to commit message"));
+ goto leave;
+ }
+ }
+
if (!opts->no_commit && !drop_commit) {
if (author || command == TODO_REVERT || (flags & AMEND_MSG))
res = do_commit(r, msg_file, author, reflog_action,
diff --git a/sequencer.h b/sequencer.h
index 304ba4b4d3..28f2da6375 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -4,6 +4,7 @@
#include "strbuf.h"
#include "strvec.h"
#include "wt-status.h"
+#include <stddef.h>
struct commit;
struct index_state;
@@ -44,6 +45,7 @@ struct replay_opts {
int record_origin;
int no_commit;
int signoff;
+ struct strvec trailer_args;
int allow_ff;
int allow_rerere_auto;
int allow_empty;
@@ -86,6 +88,7 @@ struct replay_opts {
.action = -1, \
.xopts = STRVEC_INIT, \
.ctx = replay_ctx_new(), \
+ .trailer_args = STRVEC_INIT, \
}
/*
diff --git a/t/meson.build b/t/meson.build
index d052fc3e23..14ba1d8d75 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -392,6 +392,7 @@ integration_tests = [
't3436-rebase-more-options.sh',
't3437-rebase-fixup-options.sh',
't3438-rebase-broken-files.sh',
+ 't3440-rebase-trailer.sh',
't3500-cherry.sh',
't3501-revert-cherry-pick.sh',
't3502-cherry-pick-merge.sh',
diff --git a/t/t3440-rebase-trailer.sh b/t/t3440-rebase-trailer.sh
new file mode 100755
index 0000000000..a580449628
--- /dev/null
+++ b/t/t3440-rebase-trailer.sh
@@ -0,0 +1,95 @@
+#!/bin/sh
+#
+
+test_description='git rebase --trailer integration tests
+We verify that --trailer on the merge/interactive/exec/root backends,
+and that it is rejected early when the apply backend is requested.'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh # test_commit_message, helpers
+
+create_expect() {
+ cat >"$1" <<-EOF
+ $2
+
+ Reviewed-by: Dev <dev@xxxxxxxxxxx>
+ EOF
+}
+
+test_expect_success 'setup repo with a small history' '
+ git commit --allow-empty -m "Initial empty commit" &&
+ test_commit first file a &&
+ test_commit second file &&
+ git checkout -b conflict-branch first &&
+ test_commit file-2 file-2 &&
+ test_commit conflict file &&
+ test_commit third file &&
+ ident="$GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>" &&
+ create_expect initial-signed "Initial empty commit" &&
+ create_expect first-signed "first" &&
+ create_expect second-signed "second" &&
+ create_expect file2-signed "file-2" &&
+ create_expect third-signed "third" &&
+ create_expect conflict-signed "conflict"
+'
+
+test_expect_success 'apply backend is rejected with --trailer' '
+ git reset --hard third &&
+ head_before=$(git rev-parse HEAD) &&
+ test_expect_code 128 \
+ git rebase --apply --trailer "Reviewed-by: Dev <dev@xxxxxxxxxxx>" \
+ HEAD^ 2>err &&
+ test_grep "requires the merge backend" err &&
+ test_cmp_rev HEAD $head_before
+'
+
+test_expect_success 'reject empty --trailer argument' '
+ git reset --hard third &&
+ test_expect_code 128 git rebase -m --trailer "" HEAD^ 2>err &&
+ test_grep "empty --trailer" err
+'
+
+test_expect_success 'reject trailer with missing key before separator' '
+ git reset --hard third &&
+ test_expect_code 128 git rebase -m --trailer ": no-key" HEAD^ 2>err &&
+ test_grep "missing key before separator" err
+'
+
+test_expect_success 'CLI trailer duplicates allowed; replace policy keeps last' '
+ git reset --hard third &&
+ git -c trailer.Bug.ifexists=replace -c trailer.Bug.ifmissing=add rebase -m --trailer "Bug: 123" --trailer "Bug: 456" HEAD~1 &&
+ git cat-file commit HEAD | grep "^Bug: 456" &&
+ git cat-file commit HEAD | grep -v "^Bug: 123"
+'
+
+test_expect_success 'multiple Signed-off-by trailers all preserved' '
+ git reset --hard third &&
+ git rebase -m \
+ --trailer "Signed-off-by: Dev A <a@xxxxxx>" \
+ --trailer "Signed-off-by: Dev B <b@xxxxxx>" HEAD~1 &&
+ git cat-file commit HEAD | grep -c "^Signed-off-by:" >count &&
+ test "$(cat count)" = 2 # two new commits
+'
+
+test_expect_success 'rebase -m --trailer adds trailer after conflicts' '
+ git reset --hard third &&
+ test_must_fail git rebase -m \
+ --trailer "Reviewed-by: Dev <dev@xxxxxxxxxxx>" \
+ second third &&
+ git checkout --theirs file &&
+ git add file &&
+ git rebase --continue &&
+ test_commit_message HEAD~2 file2-signed
+'
+
+test_expect_success 'rebase --root --trailer updates every commit' '
+ git checkout first &&
+ git rebase --root --keep-empty \
+ --trailer "Reviewed-by: Dev <dev@xxxxxxxxxxx>" &&
+ test_commit_message HEAD first-signed &&
+ test_commit_message HEAD^ initial-signed
+'
+test_done
--
2.49.0
