[4/6] rebase -i: fix --committer-date-is-author-date
diff mbox series

Message ID 20200407141125.30872-5-phillip.wood123@gmail.com
State New
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Series
  • fixup ra/rebase-i-more-options
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Commit Message

Phillip Wood April 7, 2020, 2:11 p.m. UTC
From: Phillip Wood <phillip.wood@dunelm.org.uk>

Johanathan Nieder reported that `rebase --committer-date-is-author-date`
failed with the error "invalid date format: @@2592000 +0000" when the
backend was switched to use the sequencer [1]. This is because when we
read the date from the author script file is already prefixed by '@' so
we do not need to add one. This did not show up in our tests
because once match_object_header_date() fails to match because of the
extra '@' parse_date_basic() strips the prefix and a date with more than
8 digits is parsed as a number of seconds by match_digit().

While fixing this I also noticed that we were not setting
GIT_COMMITTER_DATE in the environment when forking `git merge`. This was
untested. The tests we did have used commits where the author date was
the same as the current value $GIT_COMMITTER_DATE in the environment so
they did not test that we were actually using the author date when
creating the commit.

As we have already read GIT_AUTHOR_DATE into cmd.env_array we now use
that rather than re-reading the author-script file. I've moved the code
that handles opts->ignore date so that all the code setting the child
environment is together and changed it so we no longer set
GIT_COMMITTER_DATE twice when --ignore-date is combined with
--committer-date-is-author-date.

[1] https://lore.kernel.org/git/<20200110231436.GA24315@google.com>

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 sequencer.c                             | 68 ++++++++++---------------
 t/t3433-rebase-options-compatibility.sh | 29 +++++++++--
 2 files changed, 52 insertions(+), 45 deletions(-)

Comments

Elijah Newren April 7, 2020, 3:05 p.m. UTC | #1
On Tue, Apr 7, 2020 at 7:11 AM Phillip Wood <phillip.wood123@gmail.com> wrote:
>
> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> Johanathan Nieder reported that `rebase --committer-date-is-author-date`
> failed with the error "invalid date format: @@2592000 +0000" when the
> backend was switched to use the sequencer [1]. This is because when we
> read the date from the author script file is already prefixed by '@' so
> we do not need to add one. This did not show up in our tests
> because once match_object_header_date() fails to match because of the
> extra '@' parse_date_basic() strips the prefix and a date with more than
> 8 digits is parsed as a number of seconds by match_digit().
>
> While fixing this I also noticed that we were not setting
> GIT_COMMITTER_DATE in the environment when forking `git merge`. This was
> untested. The tests we did have used commits where the author date was
> the same as the current value $GIT_COMMITTER_DATE in the environment so
> they did not test that we were actually using the author date when
> creating the commit.
>
> As we have already read GIT_AUTHOR_DATE into cmd.env_array we now use
> that rather than re-reading the author-script file. I've moved the code
> that handles opts->ignore date so that all the code setting the child
> environment is together and changed it so we no longer set
> GIT_COMMITTER_DATE twice when --ignore-date is combined with
> --committer-date-is-author-date.
>
> [1] https://lore.kernel.org/git/<20200110231436.GA24315@google.com>
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>  sequencer.c                             | 68 ++++++++++---------------
>  t/t3433-rebase-options-compatibility.sh | 29 +++++++++--
>  2 files changed, 52 insertions(+), 45 deletions(-)
>
> diff --git a/sequencer.c b/sequencer.c
> index 763ccbbc45..56f6e49289 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -880,17 +880,6 @@ static char *get_author(const char *message)
>         return NULL;
>  }
>
> -/* Returns a "date" string that needs to be free()'d by the caller */
> -static char *read_author_date_or_null(void)
> -{
> -       char *date;
> -
> -       if (read_author_script(rebase_path_author_script(),
> -                              NULL, NULL, &date, 0))
> -               return NULL;
> -       return date;
> -}
> -
>  /* Construct a free()able author string with current time as the author date */
>  static char *ignore_author_date(const char *author)
>  {
> @@ -909,16 +898,20 @@ static char *ignore_author_date(const char *author)
>         return strbuf_detach(&new_author, NULL);
>  }
>
> -static void push_dates(struct child_process *child, int change_committer_date)
> +static const char *author_date_from_env_array(const struct argv_array *env)
>  {
> -       time_t now = time(NULL);
> -       struct strbuf date = STRBUF_INIT;
> +       int i;
> +       const char *date;
>
> -       strbuf_addf(&date, "@%"PRIuMAX, (uintmax_t)now);
> -       argv_array_pushf(&child->env_array, "GIT_AUTHOR_DATE=%s", date.buf);
> -       if (change_committer_date)
> -               argv_array_pushf(&child->env_array, "GIT_COMMITTER_DATE=%s", date.buf);
> -       strbuf_release(&date);
> +       for (i = 0; i < env->argc; i++)
> +               if (skip_prefix(env->argv[i],
> +                               "GIT_AUTHOR_DATE=", &date))
> +                       return date;

Is there any risk that GIT_AUTHOR_DATE=<somedate> will appear twice in
@child->env_array ?  If there is, should we read through the whole
list to make sure we take the last one?

> +       /*
> +        * If GIT_AUTHOR_DATE is missing we should have already errored out when
> +        * reading the script
> +        */
> +       BUG("GIT_AUTHOR_DATE missing from author script");
>  }
>
>  static const char staged_changes_advice[] =
> @@ -980,31 +973,19 @@ static int run_git_commit(struct repository *r,
>
>         cmd.git_cmd = 1;
>
> -       if (opts->committer_date_is_author_date) {
> -               int res = -1;
> -               struct strbuf datebuf = STRBUF_INIT;
> -               char *date = read_author_date_or_null();
> -
> -               if (!date)
> -                       return -1;
> -
> -               strbuf_addf(&datebuf, "@%s", date);
> -               res = setenv("GIT_COMMITTER_DATE",
> -                            opts->ignore_date ? "" : datebuf.buf, 1);
> -
> -               strbuf_release(&datebuf);
> -               free(date);
> -
> -               if (res)
> -                       return -1;
> -       }
> -
>         if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
>                 const char *gpg_opt = gpg_sign_opt_quoted(opts);
>
>                 return error(_(staged_changes_advice),
>                              gpg_opt, gpg_opt);
>         }
> +       if (opts->committer_date_is_author_date)
> +               argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
> +                                opts->ignore_date ?
> +                                "" :
> +                                author_date_from_env_array(&cmd.env_array));
> +       if (opts->ignore_date)
> +               argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
>
>         argv_array_push(&cmd.args, "commit");
>
> @@ -1014,8 +995,6 @@ static int run_git_commit(struct repository *r,
>                 argv_array_push(&cmd.args, "--amend");
>         if (opts->gpg_sign)
>                 argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
> -       if (opts->ignore_date)
> -               push_dates(&cmd, opts->committer_date_is_author_date);
>         if (defmsg)
>                 argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
>         else if (!(flags & EDIT_MSG))
> @@ -3615,6 +3594,13 @@ static int do_merge(struct repository *r,
>                         ret = error(_(staged_changes_advice), gpg_opt, gpg_opt);
>                         goto leave_merge;
>                 }
> +               if (opts->committer_date_is_author_date)
> +                       argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
> +                                        opts->ignore_date ?
> +                                        "" :
> +                                        author_date_from_env_array(&cmd.env_array));
> +               if (opts->ignore_date)
> +                       argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
>
>                 cmd.git_cmd = 1;
>                 argv_array_push(&cmd.args, "merge");
> @@ -3635,8 +3621,6 @@ static int do_merge(struct repository *r,
>                 argv_array_push(&cmd.args, git_path_merge_msg(r));
>                 if (opts->gpg_sign)
>                         argv_array_push(&cmd.args, opts->gpg_sign);
> -               if (opts->ignore_date)
> -                       push_dates(&cmd, opts->committer_date_is_author_date);
>
>                 /* Add the tips to be merged */
>                 for (j = to_merge; j; j = j->next)
> diff --git a/t/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
> index 132f577fc9..8247d01442 100755
> --- a/t/t3433-rebase-options-compatibility.sh
> +++ b/t/t3433-rebase-options-compatibility.sh
> @@ -71,15 +71,15 @@ test_expect_success '--ignore-whitespace works with interactive backend' '
>  '
>
>  test_expect_success '--committer-date-is-author-date works with am backend' '
> -       git commit --amend &&
> +       GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
>         git rebase --committer-date-is-author-date HEAD^ &&
>         git log -1 --pretty="format:%ai" >authortime &&
>         git log -1 --pretty="format:%ci" >committertime &&
>         test_cmp authortime committertime
>  '
>
>  test_expect_success '--committer-date-is-author-date works with interactive backend' '
> -       git commit --amend &&
> +       GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
>         git rebase -i --committer-date-is-author-date HEAD^ &&
>         git log -1 --pretty="format:%ai" >authortime &&
>         git log -1 --pretty="format:%ci" >committertime &&
> @@ -88,13 +88,36 @@ test_expect_success '--committer-date-is-author-date works with interactive back
>
>  test_expect_success '--committer-date-is-author-date works with rebase -r' '
>         git checkout side &&
> -       git merge --no-ff commit3 &&
> +       GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
>         git rebase -r --root --committer-date-is-author-date &&
>         git log --pretty="format:%ai" >authortime &&
>         git log --pretty="format:%ci" >committertime &&
>         test_cmp authortime committertime
>  '
>
> +test_expect_success '--committer-date-is-author-date works when forking merge' '
> +       git checkout side &&
> +       GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
> +       git rebase -r --root --strategy=resolve --committer-date-is-author-date &&
> +       git log --pretty="format:%ai" >authortime &&
> +       git log --pretty="format:%ci" >committertime &&
> +       test_cmp authortime committertime
> +
> +'
> +
> +test_expect_success '--committer-date-is-author-date works when committing conflict resolution' '
> +       git checkout commit2 &&
> +       GIT_AUTHOR_DATE="@1980 +0000" git commit --amend --only --reset-author &&
> +       git log -1 --format=%at HEAD >expect &&
> +       test_must_fail git rebase -i --committer-date-is-author-date \
> +               --onto HEAD^^ HEAD^ &&
> +       echo resolved > foo &&
> +       git add foo &&
> +       git rebase --continue &&
> +       git log -1 --format=%ct HEAD >actual &&
> +       test_cmp expect actual
> +'
> +
>  # Checking for +0000 in author time is enough since default
>  # timezone is UTC, but the timezone used while committing
>  # sets to +0530.
> --
> 2.26.0
>
Phillip Wood April 7, 2020, 6:11 p.m. UTC | #2
Hi Elijah

On 07/04/2020 16:05, Elijah Newren wrote:
> On Tue, Apr 7, 2020 at 7:11 AM Phillip Wood <phillip.wood123@gmail.com> wrote:
>>
>> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>>
>> Johanathan Nieder reported that `rebase --committer-date-is-author-date`
>> failed with the error "invalid date format: @@2592000 +0000" when the
>> backend was switched to use the sequencer [1]. This is because when we
>> read the date from the author script file is already prefixed by '@' so
>> we do not need to add one. This did not show up in our tests
>> because once match_object_header_date() fails to match because of the
>> extra '@' parse_date_basic() strips the prefix and a date with more than
>> 8 digits is parsed as a number of seconds by match_digit().
>>
>> While fixing this I also noticed that we were not setting
>> GIT_COMMITTER_DATE in the environment when forking `git merge`. This was
>> untested. The tests we did have used commits where the author date was
>> the same as the current value $GIT_COMMITTER_DATE in the environment so
>> they did not test that we were actually using the author date when
>> creating the commit.
>>
>> As we have already read GIT_AUTHOR_DATE into cmd.env_array we now use
>> that rather than re-reading the author-script file. I've moved the code
>> that handles opts->ignore date so that all the code setting the child
>> environment is together and changed it so we no longer set
>> GIT_COMMITTER_DATE twice when --ignore-date is combined with
>> --committer-date-is-author-date.
>>
>> [1] https://lore.kernel.org/git/<20200110231436.GA24315@google.com>
>>
>> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
>> ---
>>  sequencer.c                             | 68 ++++++++++---------------
>>  t/t3433-rebase-options-compatibility.sh | 29 +++++++++--
>>  2 files changed, 52 insertions(+), 45 deletions(-)
>>
>> diff --git a/sequencer.c b/sequencer.c
>> index 763ccbbc45..56f6e49289 100644
>> --- a/sequencer.c
>> +++ b/sequencer.c
>> @@ -880,17 +880,6 @@ static char *get_author(const char *message)
>>         return NULL;
>>  }
>>
>> -/* Returns a "date" string that needs to be free()'d by the caller */
>> -static char *read_author_date_or_null(void)
>> -{
>> -       char *date;
>> -
>> -       if (read_author_script(rebase_path_author_script(),
>> -                              NULL, NULL, &date, 0))
>> -               return NULL;
>> -       return date;
>> -}
>> -
>>  /* Construct a free()able author string with current time as the author date */
>>  static char *ignore_author_date(const char *author)
>>  {
>> @@ -909,16 +898,20 @@ static char *ignore_author_date(const char *author)
>>         return strbuf_detach(&new_author, NULL);
>>  }
>>
>> -static void push_dates(struct child_process *child, int change_committer_date)
>> +static const char *author_date_from_env_array(const struct argv_array *env)
>>  {
>> -       time_t now = time(NULL);
>> -       struct strbuf date = STRBUF_INIT;
>> +       int i;
>> +       const char *date;
>>
>> -       strbuf_addf(&date, "@%"PRIuMAX, (uintmax_t)now);
>> -       argv_array_pushf(&child->env_array, "GIT_AUTHOR_DATE=%s", date.buf);
>> -       if (change_committer_date)
>> -               argv_array_pushf(&child->env_array, "GIT_COMMITTER_DATE=%s", date.buf);
>> -       strbuf_release(&date);
>> +       for (i = 0; i < env->argc; i++)
>> +               if (skip_prefix(env->argv[i],
>> +                               "GIT_AUTHOR_DATE=", &date))
>> +                       return date;
> 
> Is there any risk that GIT_AUTHOR_DATE=<somedate> will appear twice in
> @child->env_array ?  If there is, should we read through the whole
> list to make sure we take the last one?

read_author_script() errors out if GIT_AUTHOR_DATE is missing or given
more than once

Best Wishes

Phillip

> 
>> +       /*
>> +        * If GIT_AUTHOR_DATE is missing we should have already errored out when
>> +        * reading the script
>> +        */
>> +       BUG("GIT_AUTHOR_DATE missing from author script");
>>  }
>>
>>  static const char staged_changes_advice[] =
>> @@ -980,31 +973,19 @@ static int run_git_commit(struct repository *r,
>>
>>         cmd.git_cmd = 1;
>>
>> -       if (opts->committer_date_is_author_date) {
>> -               int res = -1;
>> -               struct strbuf datebuf = STRBUF_INIT;
>> -               char *date = read_author_date_or_null();
>> -
>> -               if (!date)
>> -                       return -1;
>> -
>> -               strbuf_addf(&datebuf, "@%s", date);
>> -               res = setenv("GIT_COMMITTER_DATE",
>> -                            opts->ignore_date ? "" : datebuf.buf, 1);
>> -
>> -               strbuf_release(&datebuf);
>> -               free(date);
>> -
>> -               if (res)
>> -                       return -1;
>> -       }
>> -
>>         if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
>>                 const char *gpg_opt = gpg_sign_opt_quoted(opts);
>>
>>                 return error(_(staged_changes_advice),
>>                              gpg_opt, gpg_opt);
>>         }
>> +       if (opts->committer_date_is_author_date)
>> +               argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
>> +                                opts->ignore_date ?
>> +                                "" :
>> +                                author_date_from_env_array(&cmd.env_array));
>> +       if (opts->ignore_date)
>> +               argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
>>
>>         argv_array_push(&cmd.args, "commit");
>>
>> @@ -1014,8 +995,6 @@ static int run_git_commit(struct repository *r,
>>                 argv_array_push(&cmd.args, "--amend");
>>         if (opts->gpg_sign)
>>                 argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
>> -       if (opts->ignore_date)
>> -               push_dates(&cmd, opts->committer_date_is_author_date);
>>         if (defmsg)
>>                 argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
>>         else if (!(flags & EDIT_MSG))
>> @@ -3615,6 +3594,13 @@ static int do_merge(struct repository *r,
>>                         ret = error(_(staged_changes_advice), gpg_opt, gpg_opt);
>>                         goto leave_merge;
>>                 }
>> +               if (opts->committer_date_is_author_date)
>> +                       argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
>> +                                        opts->ignore_date ?
>> +                                        "" :
>> +                                        author_date_from_env_array(&cmd.env_array));
>> +               if (opts->ignore_date)
>> +                       argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
>>
>>                 cmd.git_cmd = 1;
>>                 argv_array_push(&cmd.args, "merge");
>> @@ -3635,8 +3621,6 @@ static int do_merge(struct repository *r,
>>                 argv_array_push(&cmd.args, git_path_merge_msg(r));
>>                 if (opts->gpg_sign)
>>                         argv_array_push(&cmd.args, opts->gpg_sign);
>> -               if (opts->ignore_date)
>> -                       push_dates(&cmd, opts->committer_date_is_author_date);
>>
>>                 /* Add the tips to be merged */
>>                 for (j = to_merge; j; j = j->next)
>> diff --git a/t/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
>> index 132f577fc9..8247d01442 100755
>> --- a/t/t3433-rebase-options-compatibility.sh
>> +++ b/t/t3433-rebase-options-compatibility.sh
>> @@ -71,15 +71,15 @@ test_expect_success '--ignore-whitespace works with interactive backend' '
>>  '
>>
>>  test_expect_success '--committer-date-is-author-date works with am backend' '
>> -       git commit --amend &&
>> +       GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
>>         git rebase --committer-date-is-author-date HEAD^ &&
>>         git log -1 --pretty="format:%ai" >authortime &&
>>         git log -1 --pretty="format:%ci" >committertime &&
>>         test_cmp authortime committertime
>>  '
>>
>>  test_expect_success '--committer-date-is-author-date works with interactive backend' '
>> -       git commit --amend &&
>> +       GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
>>         git rebase -i --committer-date-is-author-date HEAD^ &&
>>         git log -1 --pretty="format:%ai" >authortime &&
>>         git log -1 --pretty="format:%ci" >committertime &&
>> @@ -88,13 +88,36 @@ test_expect_success '--committer-date-is-author-date works with interactive back
>>
>>  test_expect_success '--committer-date-is-author-date works with rebase -r' '
>>         git checkout side &&
>> -       git merge --no-ff commit3 &&
>> +       GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
>>         git rebase -r --root --committer-date-is-author-date &&
>>         git log --pretty="format:%ai" >authortime &&
>>         git log --pretty="format:%ci" >committertime &&
>>         test_cmp authortime committertime
>>  '
>>
>> +test_expect_success '--committer-date-is-author-date works when forking merge' '
>> +       git checkout side &&
>> +       GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
>> +       git rebase -r --root --strategy=resolve --committer-date-is-author-date &&
>> +       git log --pretty="format:%ai" >authortime &&
>> +       git log --pretty="format:%ci" >committertime &&
>> +       test_cmp authortime committertime
>> +
>> +'
>> +
>> +test_expect_success '--committer-date-is-author-date works when committing conflict resolution' '
>> +       git checkout commit2 &&
>> +       GIT_AUTHOR_DATE="@1980 +0000" git commit --amend --only --reset-author &&
>> +       git log -1 --format=%at HEAD >expect &&
>> +       test_must_fail git rebase -i --committer-date-is-author-date \
>> +               --onto HEAD^^ HEAD^ &&
>> +       echo resolved > foo &&
>> +       git add foo &&
>> +       git rebase --continue &&
>> +       git log -1 --format=%ct HEAD >actual &&
>> +       test_cmp expect actual
>> +'
>> +
>>  # Checking for +0000 in author time is enough since default
>>  # timezone is UTC, but the timezone used while committing
>>  # sets to +0530.
>> --
>> 2.26.0
>>

Patch
diff mbox series

diff --git a/sequencer.c b/sequencer.c
index 763ccbbc45..56f6e49289 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -880,17 +880,6 @@  static char *get_author(const char *message)
 	return NULL;
 }
 
-/* Returns a "date" string that needs to be free()'d by the caller */
-static char *read_author_date_or_null(void)
-{
-	char *date;
-
-	if (read_author_script(rebase_path_author_script(),
-			       NULL, NULL, &date, 0))
-		return NULL;
-	return date;
-}
-
 /* Construct a free()able author string with current time as the author date */
 static char *ignore_author_date(const char *author)
 {
@@ -909,16 +898,20 @@  static char *ignore_author_date(const char *author)
 	return strbuf_detach(&new_author, NULL);
 }
 
-static void push_dates(struct child_process *child, int change_committer_date)
+static const char *author_date_from_env_array(const struct argv_array *env)
 {
-	time_t now = time(NULL);
-	struct strbuf date = STRBUF_INIT;
+	int i;
+	const char *date;
 
-	strbuf_addf(&date, "@%"PRIuMAX, (uintmax_t)now);
-	argv_array_pushf(&child->env_array, "GIT_AUTHOR_DATE=%s", date.buf);
-	if (change_committer_date)
-		argv_array_pushf(&child->env_array, "GIT_COMMITTER_DATE=%s", date.buf);
-	strbuf_release(&date);
+	for (i = 0; i < env->argc; i++)
+		if (skip_prefix(env->argv[i],
+				"GIT_AUTHOR_DATE=", &date))
+			return date;
+	/*
+	 * If GIT_AUTHOR_DATE is missing we should have already errored out when
+	 * reading the script
+	 */
+	BUG("GIT_AUTHOR_DATE missing from author script");
 }
 
 static const char staged_changes_advice[] =
@@ -980,31 +973,19 @@  static int run_git_commit(struct repository *r,
 
 	cmd.git_cmd = 1;
 
-	if (opts->committer_date_is_author_date) {
-		int res = -1;
-		struct strbuf datebuf = STRBUF_INIT;
-		char *date = read_author_date_or_null();
-
-		if (!date)
-			return -1;
-
-		strbuf_addf(&datebuf, "@%s", date);
-		res = setenv("GIT_COMMITTER_DATE",
-			     opts->ignore_date ? "" : datebuf.buf, 1);
-
-		strbuf_release(&datebuf);
-		free(date);
-
-		if (res)
-			return -1;
-	}
-
 	if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
 		const char *gpg_opt = gpg_sign_opt_quoted(opts);
 
 		return error(_(staged_changes_advice),
 			     gpg_opt, gpg_opt);
 	}
+	if (opts->committer_date_is_author_date)
+		argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+				 opts->ignore_date ?
+				 "" :
+				 author_date_from_env_array(&cmd.env_array));
+	if (opts->ignore_date)
+		argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
 
 	argv_array_push(&cmd.args, "commit");
 
@@ -1014,8 +995,6 @@  static int run_git_commit(struct repository *r,
 		argv_array_push(&cmd.args, "--amend");
 	if (opts->gpg_sign)
 		argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
-	if (opts->ignore_date)
-		push_dates(&cmd, opts->committer_date_is_author_date);
 	if (defmsg)
 		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 	else if (!(flags & EDIT_MSG))
@@ -3615,6 +3594,13 @@  static int do_merge(struct repository *r,
 			ret = error(_(staged_changes_advice), gpg_opt, gpg_opt);
 			goto leave_merge;
 		}
+		if (opts->committer_date_is_author_date)
+			argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+					 opts->ignore_date ?
+					 "" :
+					 author_date_from_env_array(&cmd.env_array));
+		if (opts->ignore_date)
+			argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
 
 		cmd.git_cmd = 1;
 		argv_array_push(&cmd.args, "merge");
@@ -3635,8 +3621,6 @@  static int do_merge(struct repository *r,
 		argv_array_push(&cmd.args, git_path_merge_msg(r));
 		if (opts->gpg_sign)
 			argv_array_push(&cmd.args, opts->gpg_sign);
-		if (opts->ignore_date)
-			push_dates(&cmd, opts->committer_date_is_author_date);
 
 		/* Add the tips to be merged */
 		for (j = to_merge; j; j = j->next)
diff --git a/t/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
index 132f577fc9..8247d01442 100755
--- a/t/t3433-rebase-options-compatibility.sh
+++ b/t/t3433-rebase-options-compatibility.sh
@@ -71,15 +71,15 @@  test_expect_success '--ignore-whitespace works with interactive backend' '
 '
 
 test_expect_success '--committer-date-is-author-date works with am backend' '
-	git commit --amend &&
+	GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
 	git rebase --committer-date-is-author-date HEAD^ &&
 	git log -1 --pretty="format:%ai" >authortime &&
 	git log -1 --pretty="format:%ci" >committertime &&
 	test_cmp authortime committertime
 '
 
 test_expect_success '--committer-date-is-author-date works with interactive backend' '
-	git commit --amend &&
+	GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
 	git rebase -i --committer-date-is-author-date HEAD^ &&
 	git log -1 --pretty="format:%ai" >authortime &&
 	git log -1 --pretty="format:%ci" >committertime &&
@@ -88,13 +88,36 @@  test_expect_success '--committer-date-is-author-date works with interactive back
 
 test_expect_success '--committer-date-is-author-date works with rebase -r' '
 	git checkout side &&
-	git merge --no-ff commit3 &&
+	GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
 	git rebase -r --root --committer-date-is-author-date &&
 	git log --pretty="format:%ai" >authortime &&
 	git log --pretty="format:%ci" >committertime &&
 	test_cmp authortime committertime
 '
 
+test_expect_success '--committer-date-is-author-date works when forking merge' '
+	git checkout side &&
+	GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
+	git rebase -r --root --strategy=resolve --committer-date-is-author-date &&
+	git log --pretty="format:%ai" >authortime &&
+	git log --pretty="format:%ci" >committertime &&
+	test_cmp authortime committertime
+
+'
+
+test_expect_success '--committer-date-is-author-date works when committing conflict resolution' '
+	git checkout commit2 &&
+	GIT_AUTHOR_DATE="@1980 +0000" git commit --amend --only --reset-author &&
+	git log -1 --format=%at HEAD >expect &&
+	test_must_fail git rebase -i --committer-date-is-author-date \
+		--onto HEAD^^ HEAD^ &&
+	echo resolved > foo &&
+	git add foo &&
+	git rebase --continue &&
+	git log -1 --format=%ct HEAD >actual &&
+	test_cmp expect actual
+'
+
 # Checking for +0000 in author time is enough since default
 # timezone is UTC, but the timezone used while committing
 # sets to +0530.