commit: allow -m/-F for all kinds of --fixup
The ability to provide a commit message for git commit --fixup and its variations is limited: * Plain --fixup only allows using the -m flag * The amend/reword --fixup variants only allow supplying the message using an editor For amend/reword, the -m and -F flags are rejected: -m is caught by a die() in prepare_to_commit(), and -F is caught by die_for_incompatible_opt4() which groups -F with --fixup as mutually exclusive. This makes these modes poorly suited for non-interactive workflows -- notably when using AI coding agents. When support to use the -m option was introduced in [1] it was noted that there could be support for other options but at the time the use case was deemed too niche. Later, when the amend suboption was introduced in [2] -m support for amend fixups was discussed but not pursued, and -F was already caught by the higher-layer incompatibility check grouping it with --fixup. The rejections of these options hark back to when --fixup was introduced in [3] and as noted in [1] -- there's nothing inherently preventing support for them. The current patchwork of which flags work with which --fixup variants has no strong logic to it, and allowing all of them simplifies both the code and the interface. Allow -m and -F to supply the message body for all --fixup variations, mirroring the flow of a regular commit. -c and -C, which are blocked by the same incompatibility check, are handled in the next commit. 1. 30884c9afc (commit: add support for --fixup <commit> -m"<extra message>", 2017-12-22) 2. 494d314a05 (commit: add amend suboption to --fixup to create amend! commit, 2021-03-15) 3. d71b8ba7c9 (commit: --fixup option for use with rebase --autosquash, 2010-11-02) Helped-by: Junio C Hamano <gitster@pobox.com> Suggested-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Erik Cervin-Edin <erik@cervined.in> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Erik Cervin-Edin committed
May 26, 2026 at 12:47 UTC
30eb1e6579559f5fc3127b32c5e9b55b5b418cd6
3 files changed
+69
-40
Documentation/git-commit.adoc
+10
-9
@@ -103,20 +103,21 @@ include::diff-context-options.adoc[]
103
The commit created by plain `--fixup=<commit>` has a title
104
composed of "fixup!" followed by the title of _<commit>_,
105
and is recognized specially by `git rebase --autosquash`. The `-m`
106
-option may be used to supplement the log message of the created
107
-commit, but the additional commentary will be thrown away once the
108
-"fixup!" commit is squashed into _<commit>_ by
106
+or `-F` option may be used to supplement the log message
107
+of the created commit, but the additional commentary will be thrown
108
+away once the "fixup!" commit is squashed into _<commit>_ by
109
`git rebase --autosquash`.
110
+
111
The commit created by `--fixup=amend:<commit>` is similar but its
112
title is instead prefixed with "amend!". The log message of
113
_<commit>_ is copied into the log message of the "amend!" commit and
114
-opened in an editor so it can be refined. When `git rebase
115
---autosquash` squashes the "amend!" commit into _<commit>_, the
116
-log message of _<commit>_ is replaced by the refined log message
117
-from the "amend!" commit. It is an error for the "amend!" commit's
118
-log message to be empty unless `--allow-empty-message` is
119
-specified.
114
+opened in an editor so it can be refined. The replacement message may
115
+also be supplied directly using `-m` or `-F`, bypassing the
116
+need to open an editor. When `git rebase
117
+--autosquash` squashes the "amend!" commit into _<commit>_, the log
118
+message of _<commit>_ is replaced by the refined log message from the
119
+"amend!" commit. It is an error for the "amend!" commit's log message
120
+to be empty unless `--allow-empty-message` is specified.
121
+
122
`--fixup=reword:<commit>` is shorthand for `--fixup=amend:<commit>
123
--only`. It creates an "amend!" commit with only a log message
builtin/commit.c
+17
-17
@@ -804,18 +804,18 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
804
if (have_option_m && !fixup_message) {
805
strbuf_addbuf(&sb, &message);
806
hook_arg1 = "message";
807
- } else if (logfile && !strcmp(logfile, "-")) {
807
+ } else if (logfile && !fixup_message && !strcmp(logfile, "-")) {
808
if (isatty(0))
809
fprintf(stderr, _("(reading log message from standard input)\n"));
810
if (strbuf_read(&sb, 0, 0) < 0)
811
die_errno(_("could not read log from standard input"));
812
hook_arg1 = "message";
813
- } else if (logfile) {
813
+ } else if (logfile && !fixup_message) {
814
if (strbuf_read_file(&sb, logfile, 0) < 0)
815
die_errno(_("could not read log file '%s'"),
816
logfile);
817
hook_arg1 = "message";
818
- } else if (use_message) {
818
+ } else if (use_message && !fixup_message) {
819
const char *buffer;
820
buffer = strstr(use_message_buffer, "\n\n");
821
if (buffer)
@@ -837,20 +837,21 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
837
hook_arg1 = "message";
838
839
/*
840
- * Only `-m` commit message option is checked here, as
841
- * it supports `--fixup` to append the commit message.
842
- *
843
- * The other commit message options `-c`/`-C`/`-F` are
844
- * incompatible with all the forms of `--fixup` and
845
- * have already errored out while parsing the `git commit`
846
- * options.
840
+ * Only `-m` and `-F` are handled here. `-c`/`-C` are
841
+ * incompatible with --fixup and have already errored out
842
+ * during option parsing.
843
*/
848
- if (have_option_m && !strcmp(fixup_prefix, "fixup"))
844
+ if (have_option_m) {
845
strbuf_addbuf(&sb, &message);
850
-
851
- if (!strcmp(fixup_prefix, "amend")) {
852
- if (have_option_m)
853
- die(_("options '%s' and '%s:%s' cannot be used together"), "-m", "--fixup", fixup_message);
846
+ } else if (logfile && !strcmp(logfile, "-")) {
847
+ if (isatty(0))
848
+ fprintf(stderr, _("(reading log message from standard input)\n"));
849
+ if (strbuf_read(&sb, 0, 0) < 0)
850
+ die_errno(_("could not read log from standard input"));
851
+ } else if (logfile) {
852
+ if (strbuf_read_file(&sb, logfile, 0) < 0)
853
+ die_errno(_("could not read log file '%s'"), logfile);
854
+ } else if (!strcmp(fixup_prefix, "amend")) {
855
prepare_amend_commit(commit, &sb, &ctx);
856
}
857
} else if (!stat(git_path_merge_msg(the_repository), &statbuf)) {
@@ -1338,9 +1339,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
1339
}
1340
if (fixup_message && squash_message)
1341
die(_("options '%s' and '%s' cannot be used together"), "--squash", "--fixup");
1341
- die_for_incompatible_opt4(!!use_message, "-C",
1342
+ die_for_incompatible_opt3(!!use_message, "-C",
1343
!!edit_message, "-c",
1343
- !!logfile, "-F",
1344
!!fixup_message, "--fixup");
1345
die_for_incompatible_opt4(have_option_m, "-m",
1346
!!edit_message, "-c",
t/t7500-commit-template-squash-signoff.sh
+42
-14
@@ -384,18 +384,24 @@ test_expect_success '--fixup=reword: ignores staged changes' '
384
test_cmp foo actual
385
'
386
387
-test_expect_success '--fixup=reword: error out with -m option' '
387
+test_expect_success 'commit --fixup=reword: works with -m' '
388
commit_for_rebase_autosquash_setup &&
389
- echo "fatal: options '\''-m'\'' and '\''--fixup:reword'\'' cannot be used together" >expect &&
390
- test_must_fail git commit --fixup=reword:HEAD~ -m "reword commit message" 2>actual &&
391
- test_cmp expect actual
389
+ git commit --fixup=reword:HEAD~ -m "reword commit message" &&
390
+ test_commit_message HEAD <<-EOF
391
+ amend! $(git log -1 --format=%s HEAD~2)
392
+
393
+ reword commit message
394
+ EOF
395
'
396
394
-test_expect_success '--fixup=amend: error out with -m option' '
397
+test_expect_success 'commit --fixup=amend: works with -m' '
398
commit_for_rebase_autosquash_setup &&
396
- echo "fatal: options '\''-m'\'' and '\''--fixup:amend'\'' cannot be used together" >expect &&
397
- test_must_fail git commit --fixup=amend:HEAD~ -m "amend commit message" 2>actual &&
398
- test_cmp expect actual
399
+ git commit --fixup=amend:HEAD~ -m "amend commit message" &&
400
+ test_commit_message HEAD <<-EOF
401
+ amend! $(git log -1 --format=%s HEAD~2)
402
+
403
+ amend commit message
404
+ EOF
405
'
406
407
test_expect_success 'consecutive amend! commits remove amend! line from commit msg body' '
@@ -432,6 +438,13 @@ test_expect_success 'deny to create amend! commit if its commit msg body is empt
438
test_cmp expected actual
439
'
440
441
+test_expect_success 'deny to create amend! commit if -m is empty' '
442
+ commit_for_rebase_autosquash_setup &&
443
+ echo "Aborting commit due to empty commit message body." >expect &&
444
+ test_must_fail git commit --fixup=amend:HEAD~ -m "" 2>actual &&
445
+ test_cmp expect actual
446
+'
447
+
448
test_expect_success 'amend! commit allows empty commit msg body with --allow-empty-message' '
449
commit_for_rebase_autosquash_setup &&
450
cat >expected <<-EOF &&
@@ -468,10 +481,26 @@ test_expect_success '--fixup=reword: give error with pathsec' '
481
test_cmp expect actual
482
'
483
471
-test_expect_success '--fixup=reword: -F give error message' '
472
- echo "fatal: options '\''-F'\'' and '\''--fixup'\'' cannot be used together" >expect &&
473
- test_must_fail git commit --fixup=reword:HEAD~ -F msg 2>actual &&
474
- test_cmp expect actual
484
+test_expect_success 'commit --fixup works with -F' '
485
+ commit_for_rebase_autosquash_setup &&
486
+ echo "message" >msgfile &&
487
+ git commit --fixup HEAD~ -F msgfile &&
488
+ test_commit_message HEAD <<-EOF
489
+ fixup! $(git log -1 --format=%s HEAD~2)
490
+
491
+ message
492
+ EOF
493
+'
494
+
495
+test_expect_success 'commit --fixup=reword: works with -F' '
496
+ commit_for_rebase_autosquash_setup &&
497
+ echo "message from file" >msgfile &&
498
+ git commit --fixup=reword:HEAD~ -F msgfile &&
499
+ test_commit_message HEAD <<-EOF
500
+ amend! $(git log -1 --format=%s HEAD~2)
501
+
502
+ $(cat msgfile)
503
+ EOF
504
'
505
506
test_expect_success 'commit --squash works with -F' '
@@ -526,8 +555,7 @@ test_expect_success 'invalid message options when using --fixup' '
555
git add foo &&
556
test_must_fail git commit --fixup HEAD~1 --squash HEAD~2 &&
557
test_must_fail git commit --fixup HEAD~1 -C HEAD~2 &&
529
- test_must_fail git commit --fixup HEAD~1 -c HEAD~2 &&
530
- test_must_fail git commit --fixup HEAD~1 -F log
558
+ test_must_fail git commit --fixup HEAD~1 -c HEAD~2
559
'
560
561
cat >expected-template <<EOF