Subject: Re: [PATCH v4 5/6] rebase -i: support --ignore-date

From: Phillip Wood <[email-masked]>
Date: Fri, 27 Sep 2019 11:00:58 +0100

Hi Rohit

This is an improvement but there are a couple of outstanding issues from 
the previous round with regard to handing --ignore-date when 
GIT_COMMITTER_DATE is set. I'll try and look at the rest of the series soon.

On 07/09/2019 12:50, Rohit Ashiwal wrote:
> rebase am already has this flag to "lie" about the author date
> by changing it to the committer (current) date. Let's add the same
> for interactive machinery.
> 
> Signed-off-by: Rohit Ashiwal <[email-masked]>
> ---
>  Documentation/git-rebase.txt            |  6 +--
>  builtin/rebase.c                        | 18 ++++++---
>  sequencer.c                             | 53 ++++++++++++++++++++++++-
>  sequencer.h                             |  1 +
>  t/t3433-rebase-options-compatibility.sh | 35 ++++++++++++++++
>  5 files changed, 104 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
> index e7c0eac18c..e7ac9fae0b 100644
> --- a/Documentation/git-rebase.txt
> +++ b/Documentation/git-rebase.txt
> @@ -391,8 +391,8 @@ See also INCOMPATIBLE OPTIONS below.
>  	as the committer date. This implies --force-rebase.
>  
>  --ignore-date::
> -	This flag is passed to 'git am' to change the author date
> -	of each rebased commit (see linkgit:git-am[1]).
> +	Instead of using the given author date, reset it to the value
> +	same as the current time. This implies --force-rebase.

s/value same as the// as Junio suggested in [1]

[1]
https://public-inbox.org/git/[email-masked]/T/#m88cf5f28110c56cf81c338c507b1d8e901b4bd6a

>  +
>  See also INCOMPATIBLE OPTIONS below.
>  
> @@ -529,7 +529,6 @@ INCOMPATIBLE OPTIONS
>  
>  The following options:
>  
> - * --ignore-date
>   * --whitespace
>   * -C
>  
> @@ -555,6 +554,7 @@ In addition, the following pairs of options are incompatible:
>   * --preserve-merges and --rebase-merges
>   * --preserve-merges and --ignore-whitespace
>   * --preserve-merges and --committer-date-is-author-date
> + * --preserve-merges and --ignore-date
>   * --rebase-merges and --ignore-whitespace
>   * --rebase-merges and --strategy
>   * --rebase-merges and --strategy-option
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 656bc7d7e9..e6f90f61dd 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -83,6 +83,7 @@ struct rebase_options {
>  	char *gpg_sign_opt;
>  	int autostash;
>  	int committer_date_is_author_date;
> +	int ignore_date;
>  	char *cmd;
>  	int allow_empty_message;
>  	int rebase_merges, rebase_cousins;
> @@ -117,6 +118,7 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
>  	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
>  	replay.committer_date_is_author_date =
>  					opts->committer_date_is_author_date;
> +	replay.ignore_date = opts->ignore_date;
>  	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
>  	replay.strategy = opts->strategy;
>  
> @@ -981,6 +983,8 @@ static int run_am(struct rebase_options *opts)
>  		argv_array_push(&am.args, "--ignore-whitespace");
>  	if (opts->committer_date_is_author_date)
>  		argv_array_push(&opts->git_am_opts, "--committer-date-is-author-date");
> +	if (opts->ignore_date)
> +		argv_array_push(&opts->git_am_opts, "--ignore-date");
>  	if (opts->action && !strcmp("continue", opts->action)) {
>  		argv_array_push(&am.args, "--resolved");
>  		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
> @@ -1427,8 +1431,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  		OPT_BOOL(0, "committer-date-is-author-date",
>  			 &options.committer_date_is_author_date,
>  			 N_("make committer date match author date")),
> -		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
> -				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
> +		OPT_BOOL(0, "ignore-date", &options.ignore_date,
> +			 "ignore author date and use current date"),
>  		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
>  				  N_("passed to 'git apply'"), 0),
>  		OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
> @@ -1697,13 +1701,17 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>  		    state_dir_base, cmd_live_rebase, buf.buf);
>  	}
>  
> -	if (options.committer_date_is_author_date)
> +	if (options.ignore_date) {
> +		options.committer_date_is_author_date = 0;
> +		setenv("GIT_COMMITTER_DATE", "", 1);
> +	}

What if GIT_COMMITTER_DATE is set? We want to match the behavior of git
am in that case. cf [2]

[2] 
https://public-inbox.org/git/[email-masked]/T/#m4f5a58fdbdb8797c5fddc5ac1b1145dbe4d01263

> +	if (options.committer_date_is_author_date ||
> +	    options.ignore_date)
>  		options.flags |= REBASE_FORCE;
>  
>  	for (i = 0; i < options.git_am_opts.argc; i++) {
>  		const char *option = options.git_am_opts.argv[i], *p;
> -		if (!strcmp(option, "--ignore-date") ||
> -		    !strcmp(option, "--whitespace=fix") ||
> +		if (!strcmp(option, "--whitespace=fix") ||
>  		    !strcmp(option, "--whitespace=strip"))
>  			options.flags |= REBASE_FORCE;
>  		else if (skip_prefix(option, "-C", &p)) {
> diff --git a/sequencer.c b/sequencer.c
> index 0d78abeec8..188499190f 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -148,6 +148,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
>   */
>  static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
>  static GIT_PATH_FUNC(rebase_path_cdate_is_adate, "rebase-merge/cdate_is_adate")
> +static GIT_PATH_FUNC(rebase_path_ignore_date, "rebase-merge/ignore_date")
>  static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
>  static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
>  static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
> @@ -891,6 +892,35 @@ static char *read_author_date_or_null(void)
>  	return date;
>  }
>  
> +/* Construct a free()able author string with current time as the author date */
> +static char *ignore_author_date(const char *author)
> +{
> +	int len = strlen(author);
> +	struct ident_split ident;
> +	struct strbuf new_author = STRBUF_INIT;
> +
> +	if (split_ident_line(&ident, author, len) < 0) {
> +		error(_("malformed ident line"));
> +		return NULL;
> +	}

This error checking is a welcome improvement

> +	len = ident.mail_end - ident.name_begin + 1;
> +
> +	strbuf_addf(&new_author, "%.*s ", len, author);

You use ident.name_begin to calculate the length which I think is the
right thing to do but then you pass author rather than ident.name_begin
here.

> +	datestamp(&new_author);
> +	return strbuf_detach(&new_author, NULL);
> +}
> +
> +static void push_dates(struct child_process *child)
> +{
> +	time_t now = time(NULL);
> +	struct strbuf date = STRBUF_INIT;
> +
> +	strbuf_addf(&date, "@%"PRIuMAX, (uintmax_t)now);
> +	argv_array_pushf(&child->env_array, "GIT_AUTHOR_DATE=%s", date.buf);
> +	argv_array_pushf(&child->env_array, "GIT_COMMITTER_DATE=%s", date.buf);

It's nice to see the environment being used for both of these now

> +	strbuf_release(&date);
> +}
> +
>  static const char staged_changes_advice[] =
>  N_("you have staged changes in your working tree\n"
>  "If these changes are meant to be squashed into the previous commit, run:\n"
> @@ -983,6 +1013,8 @@ 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);
>  	if (defmsg)
>  		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
>  	else if (!(flags & EDIT_MSG))
> @@ -1451,6 +1483,15 @@ static int try_to_commit(struct repository *r,
>  
>  	reset_ident_date();
>  
> +	if (opts->ignore_date) {
> +		author = ignore_author_date(author);
> +		if (!author) {
> +			res = -1;
> +			goto out;
> +		}

It's good to see the error handling improved

> +		free(author_to_free);
> +		author_to_free = (char *)author;
> +	}
>  	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
>  				 oid, author, opts->gpg_sign, extra)) {
>  		res = error(_("failed to write commit object"));
> @@ -2527,6 +2568,11 @@ static int read_populate_opts(struct replay_opts *opts)
>  			opts->committer_date_is_author_date = 1;
>  		}
>  
> +		if (file_exists(rebase_path_ignore_date())) {
> +			opts->allow_ff = 0;
> +			opts->ignore_date = 1;
> +		}
> +
>  		if (file_exists(rebase_path_reschedule_failed_exec()))
>  			opts->reschedule_failed_exec = 1;
>  
> @@ -2611,6 +2657,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
>  		write_file(rebase_path_signoff(), "--signoff\n");
>  	if (opts->committer_date_is_author_date)
>  		write_file(rebase_path_cdate_is_adate(), "%s", "");
> +	if (opts->ignore_date)
> +		write_file(rebase_path_ignore_date(), "%s", "");
>  	if (opts->reschedule_failed_exec)
>  		write_file(rebase_path_reschedule_failed_exec(), "%s", "");
>  
> @@ -3536,6 +3584,8 @@ 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);
>  
>  		/* Add the tips to be merged */
>  		for (j = to_merge; j; j = j->next)
> @@ -3809,7 +3859,8 @@ static int pick_commits(struct repository *r,
>  	if (opts->allow_ff)
>  		assert(!(opts->signoff || opts->no_commit ||
>  				opts->record_origin || opts->edit ||
> -				opts->committer_date_is_author_date));
> +				opts->committer_date_is_author_date ||
> +				opts->ignore_date));
>  	if (read_and_refresh_cache(r, opts))
>  		return -1;
>  
> diff --git a/sequencer.h b/sequencer.h
> index e3881e9275..bf5a79afdb 100644
> --- a/sequencer.h
> +++ b/sequencer.h
> @@ -44,6 +44,7 @@ struct replay_opts {
>  	int quiet;
>  	int reschedule_failed_exec;
>  	int committer_date_is_author_date;
> +	int ignore_date;
>  
>  	int mainline;
>  
> diff --git a/t/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
> index 6c1fbab4d8..0ad7bfc6a0 100755
> --- a/t/t3433-rebase-options-compatibility.sh
> +++ b/t/t3433-rebase-options-compatibility.sh
> @@ -99,4 +99,39 @@ test_expect_success '--committer-date-is-author-date works with rebase -r' '
>  	done <rev_list
>  '
>  
> +# Checking for +0000 in author time is enough since default
> +# timezone is UTC, but the timezone used while committing
> +# sets to +0530.
> +test_expect_success '--ignore-date works with am backend' '
> +	git commit --amend --date="$GIT_AUTHOR_DATE" &&
> +	git rebase --ignore-date HEAD^ &&
> +	git show HEAD --pretty="format:%ai" >authortime &&
> +	git show HEAD --pretty="format:%ci" >committertime &&
> +	grep "+0000" authortime &&
> +	grep "+0000" committertime
> +'
> +
> +test_expect_success '--ignore-date works with interactive backend' '
> +	git commit --amend --date="$GIT_AUTHOR_DATE" &&
> +	git rebase --ignore-date -i HEAD^ &&
> +	git show HEAD --pretty="format:%ai" >authortime &&
> +	git show HEAD --pretty="format:%ci" >committertime &&
> +	grep "+0000" authortime &&
> +	grep "+0000" committertime
> +'
> +
> +test_expect_success '--ignore-date works with rebase -r' '
> +	git checkout side &&
> +	git merge commit3 &&
> +	git rebase -r --root --ignore-date &&
> +	git rev-list HEAD >rev_list &&
> +	while read HASH
> +	do
> +		git show $HASH --pretty="format:%ai" >authortime
> +		git show $HASH --pretty="format:%ci" >committertime
> +		grep "+0000" authortime
> +		grep "+0000" committertime
> +	done <rev_list
> +'

It's good to see the new test. Did you see Stolee's email [4] about the 
test coverage of the previous version of this series? You should check 
that this series tests all the untested non-error handling lines.

[4] 
https://public-inbox.org/git/[email-masked]/

Best Wishes

Phillip

>  test_done