diff mbox series

[v11,GSOC] commit: add --trailer option

Message ID pull.901.v11.git.1616155517590.gitgitgadget@gmail.com (mailing list archive)
State Superseded
Headers show
Series [v11,GSOC] commit: add --trailer option | expand

Commit Message

ZheNing Hu March 19, 2021, 12:05 p.m. UTC 
From: ZheNing Hu <adlternative@gmail.com>

Historically, Git has supported the 'Signed-off-by' commit trailer
using the '--signoff' and the '-s' option from the command line.
But users may need to provide other trailer information from the
command line such as "Helped-by", "Reported-by", "Mentored-by",

Now implement a new `--trailer <token>[(=|:)<value>]` option to pass
other trailers to `interpret-trailers` and insert them into commit
messages.

Signed-off-by: ZheNing Hu <adlternative@gmail.com>
---
    [GSOC] commit: add --trailer option
    
    Now maintainers or developers can also use commit
    --trailer="Signed-off-by:commiter<email>" from the command line to
    provide trailers to commit messages. This solution may be more
    generalized than v1.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-901%2Fadlternative%2Fcommit-with-multiple-signatures-v11
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-901/adlternative/commit-with-multiple-signatures-v11
Pull-Request: https://github.com/gitgitgadget/git/pull/901

Range-diff vs v10:

 1:  949faf9ee56a ! 1:  0db1210ffd6d [GSOC] commit: add --trailer option
     @@ Documentation/git-commit.txt: SYNOPSIS
       	   [--date=<date>] [--cleanup=<mode>] [--[no-]status]
       	   [-i | -o] [--pathspec-from-file=<file> [--pathspec-file-nul]]
      -	   [-S[<keyid>]] [--] [<pathspec>...]
     -+	   [-S[<keyid>]] [--] [<pathspec>...] [(--trailer <token>[(=|:)<value>])...]
     ++	   [(--trailer <token>[(=|:)<value>])...] [-S[<keyid>]]
     ++	   [--] [<pathspec>...]
       
       DESCRIPTION
       -----------
     @@ builtin/commit.c: static int prepare_to_commit(const char *index_file, const cha
      +			     "--in-place", git_path_commit_editmsg(), NULL);
      +		strvec_pushv(&run_trailer.args, trailer_args.v);
      +		run_trailer.git_cmd = 1;
     -+		if (run_command(&run_trailer)) {
     -+			die(_("unable to pass tailers to --trailers"));
     -+		}
     ++		if (run_command(&run_trailer))
     ++			die(_("unable to pass trailers to --trailers"));
      +		strvec_clear(&trailer_args);
      +	}
      +
     @@ t/t7502-commit-porcelain.sh: test_expect_success 'sign off' '
      +	test_cmp expected actual
      +'
      +
     -+test_expect_success 'commit --trailer with -c and "=" as separators' '
     ++test_expect_success 'commit --trailer with "=" ' '
      +	echo "fun" >>file1 &&
      +	git add file1 &&
      +	cat >expected <<-\EOF &&
      +
     -+		Acked-by= Peff
     ++		Acked-by: Peff
      +	EOF
     -+	git -c trailer.separators="=" \
     -+		-c trailer.ack.key="Acked-by= " \
     ++	git -c trailer.ack.key="Acked-by" \
      +		commit --trailer "ack = Peff" -m "hello" &&
      +	git cat-file commit HEAD >commit.msg &&
      +	sed -e "1,6d" commit.msg >actual &&
 2:  42590e95deee < -:  ------------ interpret-trailers: add own-identity option
 3:  2dfcc20f0e9f < -:  ------------ commit: add own-identity option


 Documentation/git-commit.txt |  11 +-
 builtin/commit.c             |  22 +++
 t/t7502-commit-porcelain.sh  | 335 +++++++++++++++++++++++++++++++++++
 3 files changed, 367 insertions(+), 1 deletion(-)


base-commit: 13d7ab6b5d7929825b626f050b62a11241ea4945

Comments

Junio C Hamano March 19, 2021, 5:48 p.m. UTC | #1 
"ZheNing Hu via GitGitGadget" <gitgitgadget@gmail.com> writes:

> +--trailer <token>[(=|:)<value>]::
> +	Specify a (<token>, <value>) pair that should be applied as a
> +	trailer. (e.g. `git commit --trailer "Signed-off-by:C O Mitter \
> +	<committer@example.com>" --trailer "Helped-by:C O Mitter \
> +	<committer@example.com>"` will add the "Signed-off-by" trailer
> +	and the "Helped-by" trailer in the commit message.)

s/in the commit message/to the commit message/ probably.

> +	Use `git -c trailer.* commit --trailer` to make the appropriate
> +	configuration. See linkgit:git-interpret-trailers[1] for details.

I doubt this is a good advice for a few reasons.

 (1) The "git -c var=val" is meant to be used as a single-shot
     oddball configuration.  If the user will be working on the
     project long enough to be worth using the --trailer option
     (otherwise a single-shot drive-by patch can just add these
     trailers while editing the log message in the editor), the user
     would not want to use "git -c var=val" mechanism to use
     different configuration every time the --trailer option is
     used.

 (2) The "appropriate configuration" is too vague and does not give
     enough incentive to the reader to go look in the other manual
     page.  At least there should be a cursory mention of what kind
     of things are possible by the configuration.

Prehaps

    The `trailer.*` configuration variables (see linkgit:...) can be
    used to define if a duplicated trailer is omitted, where in the
    run of trailers each trailer would appear, and other details.

or something along the line (Christian would be a better person to
suggest what good examples are than I am, though).

> diff --git a/builtin/commit.c b/builtin/commit.c
> index 739110c5a7f6..4b06672bd07d 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -113,6 +113,7 @@ static int config_commit_verbose = -1; /* unspecified */
>  static int no_post_rewrite, allow_empty_message, pathspec_file_nul;
>  static char *untracked_files_arg, *force_date, *ignore_submodule_arg, *ignored_arg;
>  static char *sign_commit, *pathspec_from_file;
> +static struct strvec trailer_args = STRVEC_INIT;
>  
>  /*
>   * The default commit message cleanup mode will remove the lines
> @@ -131,6 +132,14 @@ static struct strbuf message = STRBUF_INIT;
>  
>  static enum wt_status_format status_format = STATUS_FORMAT_UNSPECIFIED;
>  
> +static int opt_pass_trailer(const struct option *opt, const char *arg, int unset)
> +{
> +	BUG_ON_OPT_NEG(unset);
> +
> +	strvec_pushl(&trailer_args, "--trailer", arg, NULL);
> +	return 0;
> +}
> +
>  static int opt_parse_porcelain(const struct option *opt, const char *arg, int unset)
>  {
>  	enum wt_status_format *value = (enum wt_status_format *)opt->value;
> @@ -958,6 +967,18 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
>  
>  	fclose(s->fp);
>  
> +	if (trailer_args.nr) {
> +		struct child_process run_trailer = CHILD_PROCESS_INIT;
> +
> +		strvec_pushl(&run_trailer.args, "interpret-trailers",
> +			     "--in-place", git_path_commit_editmsg(), NULL);
> +		strvec_pushv(&run_trailer.args, trailer_args.v);
> +		run_trailer.git_cmd = 1;
> +		if (run_command(&run_trailer))
> +			die(_("unable to pass trailers to --trailers"));
> +		strvec_clear(&trailer_args);

OK.  run_command() cleans the run_trailer.args when it returns, so
we only need to clear our own array here.

> +	}
> +

> diff --git a/t/t7502-commit-porcelain.sh b/t/t7502-commit-porcelain.sh
> index 6396897cc818..024cf3c81b18 100755
> --- a/t/t7502-commit-porcelain.sh
> +++ b/t/t7502-commit-porcelain.sh
> @@ -154,6 +154,341 @@ test_expect_success 'sign off' '
>  
>  '
>  
> +test_expect_success 'commit --trailer without -c' '
> +	echo "fun" >>file &&
> +	git add file &&
> +	cat >expected <<-\EOF &&
> +
> +	Signed-off-by: C O Mitter <committer@example.com>
> +	Signed-off-by: C1 E1
> +	Helped-by: C2 E2
> +	Reported-by: C3 E3
> +	Mentored-by: C4 E4
> +	EOF
> +	git commit -s --trailer "Signed-off-by:C1 E1 " \
> +		--trailer "Helped-by:C2 E2 " \
> +		--trailer "Reported-by:C3 E3" \
> +		--trailer "Mentored-by:C4 E4" \
> +		-m "hello" &&
> +	git cat-file commit HEAD >commit.msg &&
> +	sed -e "1,6d" commit.msg >actual &&

This 1,6d depends on the exact line organization of the underlying
object detail, which is not good.  You'd want to grab the run of the
consecutive non-empty lines at the end, so that commit object headers
and the log message "fun" can change over time by changes to Git and
changes to this test, without breaking this test.

> +	test_cmp expected actual
> +'
> +
> +test_expect_success 'commit --trailer with -c and "replace" as ifexists' '
> +	echo "fun" >>file1 &&
> +	git add file1 &&
> +	cat >expected <<-\EOF &&
> +
> +	Signed-off-by: C O Mitter <committer@example.com>
> +	Signed-off-by: C1 E1
> +	Reported-by: C3 E3
> +	Mentored-by: C4 E4
> +	Helped-by: C3 E3
> +	EOF
> +	git -c trailer.ifexists="replace" \
> +		commit --trailer "Mentored-by: C4 E4" \
> +		 --trailer "Helped-by: C3 E3" \
> +		--amend &&
> +	git cat-file commit HEAD >commit.msg &&
> +	sed -e "1,6d" commit.msg >actual &&
> +	test_cmp expected actual

The same comment applies, and also by using "--amend", this relies
on the outcome of the previous test, which is not great.

> +'
> +
> +test_expect_success 'commit --trailer with -c and "add" as ifexists' '
> +	echo "fun" >>file1 &&
> +	git add file1 &&
> +	cat >expected <<-\EOF &&
> +
> +	Signed-off-by: C O Mitter <committer@example.com>
> +	Signed-off-by: C1 E1
> +	Reported-by: C3 E3
> +	Mentored-by: C4 E4
> +	Helped-by: C3 E3
> +	Helped-by: C3 E3
> +	Helped-by: C3 E3
> +	EOF
> +	git -c trailer.ifexists="add" \
> +		commit --trailer "Helped-by: C3 E3" \
> +		--trailer "Helped-by: C3 E3" \
> +		--amend &&

And it makes things worse by keep amending.

At least, establish a baseline commit that has known set of
trailers, tag it, and reset the HEAD to that commit at the beginning
of each test that tries to amend an existing commit.  That way, the
correctness of each individual test would depend only on the test
that creates the baseline commit and tags it.
diff mbox series

Patch

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 17150fa7eabe..2ba2fe0dd10e 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -14,7 +14,8 @@  SYNOPSIS
 	   [--allow-empty-message] [--no-verify] [-e] [--author=<author>]
 	   [--date=<date>] [--cleanup=<mode>] [--[no-]status]
 	   [-i | -o] [--pathspec-from-file=<file> [--pathspec-file-nul]]
-	   [-S[<keyid>]] [--] [<pathspec>...]
+	   [(--trailer <token>[(=|:)<value>])...] [-S[<keyid>]]
+	   [--] [<pathspec>...]
 
 DESCRIPTION
 -----------
@@ -166,6 +167,14 @@  The `-m` option is mutually exclusive with `-c`, `-C`, and `-F`.
 
 include::signoff-option.txt[]
 
+--trailer <token>[(=|:)<value>]::
+	Specify a (<token>, <value>) pair that should be applied as a
+	trailer. (e.g. `git commit --trailer "Signed-off-by:C O Mitter \
+	<committer@example.com>" --trailer "Helped-by:C O Mitter \
+	<committer@example.com>"` will add the "Signed-off-by" trailer
+	and the "Helped-by" trailer in the commit message.)
+	Use `git -c trailer.* commit --trailer` to make the appropriate
+	configuration. See linkgit:git-interpret-trailers[1] for details.
 -n::
 --no-verify::
 	This option bypasses the pre-commit and commit-msg hooks.
diff --git a/builtin/commit.c b/builtin/commit.c
index 739110c5a7f6..4b06672bd07d 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -113,6 +113,7 @@  static int config_commit_verbose = -1; /* unspecified */
 static int no_post_rewrite, allow_empty_message, pathspec_file_nul;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg, *ignored_arg;
 static char *sign_commit, *pathspec_from_file;
+static struct strvec trailer_args = STRVEC_INIT;
 
 /*
  * The default commit message cleanup mode will remove the lines
@@ -131,6 +132,14 @@  static struct strbuf message = STRBUF_INIT;
 
 static enum wt_status_format status_format = STATUS_FORMAT_UNSPECIFIED;
 
+static int opt_pass_trailer(const struct option *opt, const char *arg, int unset)
+{
+	BUG_ON_OPT_NEG(unset);
+
+	strvec_pushl(&trailer_args, "--trailer", arg, NULL);
+	return 0;
+}
+
 static int opt_parse_porcelain(const struct option *opt, const char *arg, int unset)
 {
 	enum wt_status_format *value = (enum wt_status_format *)opt->value;
@@ -958,6 +967,18 @@  static int prepare_to_commit(const char *index_file, const char *prefix,
 
 	fclose(s->fp);
 
+	if (trailer_args.nr) {
+		struct child_process run_trailer = CHILD_PROCESS_INIT;
+
+		strvec_pushl(&run_trailer.args, "interpret-trailers",
+			     "--in-place", git_path_commit_editmsg(), NULL);
+		strvec_pushv(&run_trailer.args, trailer_args.v);
+		run_trailer.git_cmd = 1;
+		if (run_command(&run_trailer))
+			die(_("unable to pass trailers to --trailers"));
+		strvec_clear(&trailer_args);
+	}
+
 	/*
 	 * Reject an attempt to record a non-merge empty commit without
 	 * explicit --allow-empty. In the cherry-pick case, it may be
@@ -1507,6 +1528,7 @@  int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_STRING(0, "fixup", &fixup_message, N_("commit"), N_("use autosquash formatted message to fixup specified commit")),
 		OPT_STRING(0, "squash", &squash_message, N_("commit"), N_("use autosquash formatted message to squash specified commit")),
 		OPT_BOOL(0, "reset-author", &renew_authorship, N_("the commit is authored by me now (used with -C/-c/--amend)")),
+		OPT_CALLBACK_F(0, "trailer", NULL, N_("trailer"), N_("add custom trailer(s)"), PARSE_OPT_NONEG, opt_pass_trailer),
 		OPT_BOOL('s', "signoff", &signoff, N_("add a Signed-off-by trailer")),
 		OPT_FILENAME('t', "template", &template_file, N_("use specified template file")),
 		OPT_BOOL('e', "edit", &edit_flag, N_("force edit of commit")),
diff --git a/t/t7502-commit-porcelain.sh b/t/t7502-commit-porcelain.sh
index 6396897cc818..024cf3c81b18 100755
--- a/t/t7502-commit-porcelain.sh
+++ b/t/t7502-commit-porcelain.sh
@@ -154,6 +154,341 @@  test_expect_success 'sign off' '
 
 '
 
+test_expect_success 'commit --trailer without -c' '
+	echo "fun" >>file &&
+	git add file &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Helped-by: C2 E2
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	EOF
+	git commit -s --trailer "Signed-off-by:C1 E1 " \
+		--trailer "Helped-by:C2 E2 " \
+		--trailer "Reported-by:C3 E3" \
+		--trailer "Mentored-by:C4 E4" \
+		-m "hello" &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "replace" as ifexists' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	EOF
+	git -c trailer.ifexists="replace" \
+		commit --trailer "Mentored-by: C4 E4" \
+		 --trailer "Helped-by: C3 E3" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "add" as ifexists' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	EOF
+	git -c trailer.ifexists="add" \
+		commit --trailer "Helped-by: C3 E3" \
+		--trailer "Helped-by: C3 E3" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "donothing" as ifexists' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	EOF
+	git -c trailer.ifexists="donothing" \
+		commit --trailer "Mentored-by: C5 E5" \
+		--trailer "Reviewed-by: C6 E6" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "addIfDifferent" as ifexists' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	EOF
+	git -c trailer.ifexists="addIfDifferent" \
+		commit --trailer "Reviewed-by: C6 E6" \
+		--trailer "Reported-by: C5 E5" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "addIfDifferentNeighbor" as ifexists' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	EOF
+	git -c trailer.ifexists="addIfDifferent" \
+		commit --trailer "Reported-by: C5 E5" \
+		--trailer "Reviewed-by: C6 E6" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "end" as where' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	EOF
+	git -c trailer.where="end" \
+		commit --trailer "Reported-by: C5 E5" \
+		--trailer "Reported-by: C7 E7" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "start" as where' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C8 E8
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	EOF
+	git -c trailer.where="start" \
+		commit --trailer "Signed-off-by: C8 E8" \
+		--trailer "Signed-off-by: C8 E8" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "after" as where' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C8 E8
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Mentored-by: C9 E9
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	Reported-by: C10 E10
+	EOF
+	git -c trailer.where="after" \
+		commit --trailer "Mentored-by: C9 E9" \
+		--trailer "Reported-by: C10 E10" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "before" as where' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C8 E8
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C11 E11
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Mentored-by: C9 E9
+	Helped-by: C12 E12
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	Reported-by: C10 E10
+	EOF
+	git -c trailer.where="before" \
+		commit --trailer "Helped-by: C12 E12" \
+		--trailer "Reported-by: C11 E11" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "donothing" as ifmissing' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C8 E8
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C11 E11
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Mentored-by: C9 E9
+	Helped-by: C12 E12
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	Reported-by: C10 E10
+	Helped-by: C12 E12
+	EOF
+	git -c trailer.ifmissing="donothing" \
+		commit --trailer "Helped-by: C12 E12" \
+		--trailer "Based-by: C13 E13" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and "add" as ifmissing' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+	Signed-off-by: C8 E8
+	Signed-off-by: C O Mitter <committer@example.com>
+	Signed-off-by: C1 E1
+	Reported-by: C11 E11
+	Reported-by: C3 E3
+	Mentored-by: C4 E4
+	Mentored-by: C9 E9
+	Helped-by: C12 E12
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Helped-by: C3 E3
+	Reviewed-by: C6 E6
+	Reported-by: C5 E5
+	Reported-by: C7 E7
+	Reported-by: C10 E10
+	Helped-by: C12 E12
+	Based-by: C13 E13
+	EOF
+	git -c trailer.ifmissing="add" \
+		commit --trailer "Helped-by: C12 E12" \
+		--trailer "Based-by: C13 E13" \
+		--amend &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with "=" ' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+		Acked-by: Peff
+	EOF
+	git -c trailer.ack.key="Acked-by" \
+		commit --trailer "ack = Peff" -m "hello" &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'commit --trailer with -c and ":=#" as separators' '
+	echo "fun" >>file1 &&
+	git add file1 &&
+	cat >expected <<-\EOF &&
+
+		Bug #42
+	EOF
+	git -c trailer.separators=":=#" \
+		-c trailer.bug.key="Bug #" \
+		commit --trailer "bug = 42" -m "I hate bug" &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,6d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'multiple -m' '
 
 	>negative &&