trailer: append trailers without fork/exec
Introduce amend_strbuf_with_trailers() to apply trailer additions to a message buffer via process_trailers(), avoiding the need to run git interpret-trailers as a child process. Update amend_file_with_trailers() to use the in-process helper and rewrite the target file via tempfile+rename, preserving the previous in-place semantics. As the trailers are no longer added in a separate process and trailer_config_init() die()s on missing config values it is called early on in cmd_commit() and cmd_tag() so that they die() early before writing the message file. The trailer arguments are now also sanity checked. Keep existing callers unchanged by continuing to accept argv-style --trailer=<trailer> entries and stripping the prefix before feeding the in-process implementation. Signed-off-by: Li Chen <me@linux.beauty> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Li Chen committed
Mar 6, 2026 at 14:53 UTC
6b2243fdd45f0596fc640823faaa6a1aec05a420
4 files changed
+147
-12
builtin/commit.c
+3
@@ -1820,6 +1820,9 @@ int cmd_commit(int argc,
1820
argc = parse_and_validate_options(argc, argv, builtin_commit_options,
1821
builtin_commit_usage,
1822
prefix, current_head, &s);
1823
+ if (trailer_args.nr)
1824
+ trailer_config_init();
1825
+
1826
if (verbose == -1)
1827
verbose = (config_commit_verbose < 0) ? 0 : config_commit_verbose;
1828
builtin/tag.c
+3
@@ -568,6 +568,9 @@ int cmd_tag(int argc,
568
if (cmdmode == 'l')
569
setup_auto_pager("tag", 1);
570
571
+ if (trailer_args.nr)
572
+ trailer_config_init();
573
+
574
if (opt.sign == -1)
575
opt.sign = cmdmode ? 0 : config_sign_tag > 0;
576
trailer.c
+124
-9
@@ -7,6 +7,7 @@
7
#include "string-list.h"
8
#include "run-command.h"
9
#include "commit.h"
10
+#include "strvec.h"
11
#include "trailer.h"
12
#include "list.h"
13
#include "tempfile.h"
@@ -774,6 +775,35 @@ void parse_trailers_from_command_line_args(struct list_head *arg_head,
775
free(cl_separators);
776
}
777
778
+int validate_trailer_args(const struct strvec *cli_args)
779
+{
780
+ char *cl_separators;
781
+ int ret = 0;
782
+
783
+ trailer_config_init();
784
+
785
+ cl_separators = xstrfmt("=%s", separators);
786
+
787
+ for (size_t i = 0; i < cli_args->nr; i++) {
788
+ const char *txt = cli_args->v[i];
789
+ ssize_t separator_pos;
790
+
791
+ if (!*txt) {
792
+ ret = error(_("empty --trailer argument"));
793
+ goto out;
794
+ }
795
+ separator_pos = find_separator(txt, cl_separators);
796
+ if (separator_pos == 0) {
797
+ ret = error(_("invalid trailer '%s': missing key before separator"),
798
+ txt);
799
+ goto out;
800
+ }
801
+ }
802
+out:
803
+ free(cl_separators);
804
+ return ret;
805
+}
806
+
807
static const char *next_line(const char *str)
808
{
809
const char *nl = strchrnul(str, '\n');
@@ -1258,16 +1288,101 @@ struct tempfile *trailer_create_in_place_tempfile(const char *file)
1288
return tempfile;
1289
}
1290
1261
-int amend_file_with_trailers(const char *path, const struct strvec *trailer_args)
1291
+int amend_strbuf_with_trailers(struct strbuf *buf,
1292
+ const struct strvec *trailer_args)
1293
{
1263
- struct child_process run_trailer = CHILD_PROCESS_INIT;
1264
-
1265
- run_trailer.git_cmd = 1;
1266
- strvec_pushl(&run_trailer.args, "interpret-trailers",
1267
- "--in-place", "--no-divider",
1268
- path, NULL);
1269
- strvec_pushv(&run_trailer.args, trailer_args->v);
1270
- return run_command(&run_trailer);
1294
+ struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
1295
+ LIST_HEAD(new_trailer_head);
1296
+ struct strbuf out = STRBUF_INIT;
1297
+ size_t i;
1298
+ int ret = 0;
1299
+
1300
+ opts.no_divider = 1;
1301
+
1302
+ for (i = 0; i < trailer_args->nr; i++) {
1303
+ const char *text = trailer_args->v[i];
1304
+ struct new_trailer_item *item;
1305
+
1306
+ if (!*text) {
1307
+ ret = error(_("empty --trailer argument"));
1308
+ goto out;
1309
+ }
1310
+ item = xcalloc(1, sizeof(*item));
1311
+ item->text = xstrdup(text);
1312
+ list_add_tail(&item->list, &new_trailer_head);
1313
+ }
1314
+
1315
+ process_trailers(&opts, &new_trailer_head, buf, &out);
1316
+
1317
+ strbuf_swap(buf, &out);
1318
+out:
1319
+ strbuf_release(&out);
1320
+ free_trailers(&new_trailer_head);
1321
+
1322
+ return ret;
1323
+}
1324
+
1325
+static int write_file_in_place(const char *path, const struct strbuf *buf)
1326
+{
1327
+ struct tempfile *tempfile = trailer_create_in_place_tempfile(path);
1328
+ if (!tempfile)
1329
+ return -1;
1330
+
1331
+ if (write_in_full(tempfile->fd, buf->buf, buf->len) < 0)
1332
+ return error_errno(_("could not write to temporary file"));
1333
+
1334
+ if (rename_tempfile(&tempfile, path))
1335
+ return error_errno(_("could not rename temporary file to %s"), path);
1336
+
1337
+ return 0;
1338
+}
1339
+
1340
+int amend_file_with_trailers(const char *path,
1341
+ const struct strvec *trailer_args)
1342
+{
1343
+ struct strbuf buf = STRBUF_INIT;
1344
+ struct strvec stripped_trailer_args = STRVEC_INIT;
1345
+ int ret = 0;
1346
+ size_t i;
1347
+
1348
+ if (!trailer_args)
1349
+ BUG("amend_file_with_trailers called with NULL trailer_args");
1350
+ if (!trailer_args->nr)
1351
+ return 0;
1352
+
1353
+ for (i = 0; i < trailer_args->nr; i++) {
1354
+ const char *txt = trailer_args->v[i];
1355
+
1356
+ /*
1357
+ * Historically amend_file_with_trailers() passed its arguments
1358
+ * to "git interpret-trailers", which expected argv entries in
1359
+ * "--trailer=<trailer>" form. Continue to accept those for
1360
+ * existing callers, but pass only the value portion to the
1361
+ * in-process implementation.
1362
+ */
1363
+ skip_prefix(txt, "--trailer=", &txt);
1364
+ if (!*txt) {
1365
+ ret = error(_("empty --trailer argument"));
1366
+ goto out;
1367
+ }
1368
+ strvec_push(&stripped_trailer_args, txt);
1369
+ }
1370
+
1371
+ if (validate_trailer_args(&stripped_trailer_args)) {
1372
+ ret = -1;
1373
+ goto out;
1374
+ }
1375
+ if (strbuf_read_file(&buf, path, 0) < 0)
1376
+ ret = error_errno(_("could not read '%s'"), path);
1377
+ else
1378
+ amend_strbuf_with_trailers(&buf, &stripped_trailer_args);
1379
+
1380
+ if (!ret)
1381
+ ret = write_file_in_place(path, &buf);
1382
+out:
1383
+ strvec_clear(&stripped_trailer_args);
1384
+ strbuf_release(&buf);
1385
+ return ret;
1386
}
1387
1388
void process_trailers(const struct process_trailer_options *opts,
trailer.h
+17
-3
@@ -68,6 +68,8 @@ void parse_trailers_from_config(struct list_head *config_head);
68
void parse_trailers_from_command_line_args(struct list_head *arg_head,
69
struct list_head *new_trailer_head);
70
71
+int validate_trailer_args(const struct strvec *cli_args);
72
+
73
void process_trailers_lists(struct list_head *head,
74
struct list_head *arg_head);
75
@@ -196,9 +198,21 @@ int trailer_iterator_advance(struct trailer_iterator *iter);
198
void trailer_iterator_release(struct trailer_iterator *iter);
199
200
/*
199
- * Augment a file to add trailers to it by running git-interpret-trailers.
200
- * This calls run_command() and its return value is the same (i.e. 0 for
201
- * success, various non-zero for other errors). See run-command.h.
201
+ * Append trailers specified in trailer_args to buf in-place.
202
+ *
203
+ * Each element of trailer_args should be in the same format as the value
204
+ * accepted by --trailer=<trailer> (i.e., without the --trailer= prefix).
205
+ */
206
+int amend_strbuf_with_trailers(struct strbuf *buf,
207
+ const struct strvec *trailer_args);
208
+
209
+/*
210
+ * Augment a file by appending trailers specified in trailer_args.
211
+ *
212
+ * Each element of trailer_args should be an argv-style --trailer=<trailer>
213
+ * option (i.e., including the --trailer= prefix).
214
+ *
215
+ * Returns 0 on success or a non-zero error code on failure.
216
*/
217
int amend_file_with_trailers(const char *path, const struct strvec *trailer_args);
218