Re: [PATCH 1/1] rebase: really just passthru the `git am` options

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> Currently, we parse the options intended for `git am` as if we wanted to
> handle them in `git rebase`, and then reconstruct them painstakingly to
> define the `git_am_opt` variable.
> 
> However, there is a much better way (that I was unaware of, at the time
> when I mentored Pratik to implement these options): OPT_PASSTHRU_ARGV.
> It is intended for exactly this use case, where command-line options
> want to be parsed into a separate `argv_array`.
> 
> Let's use this feature.
> 
> Incidentally, this also allows us to address a bug discovered by Phillip
> Wood, where the built-in rebase failed to understand that the `-C`
> option takes an optional argument.
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>   builtin/rebase.c | 98 +++++++++++++++++-------------------------------
>   1 file changed, 35 insertions(+), 63 deletions(-)
> 
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 0ee06aa363..96ffa80b71 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -87,7 +87,7 @@ struct rebase_options {
>   		REBASE_FORCE = 1<<3,
>   		REBASE_INTERACTIVE_EXPLICIT = 1<<4,
>   	} flags;
> -	struct strbuf git_am_opt;
> +	struct argv_array git_am_opts;
>   	const char *action;
>   	int signoff;
>   	int allow_rerere_autoupdate;
> @@ -339,7 +339,7 @@ N_("Resolve all conflicts manually, mark them as resolved with\n"
>   static int run_specific_rebase(struct rebase_options *opts)
>   {
>   	const char *argv[] = { NULL, NULL };
> -	struct strbuf script_snippet = STRBUF_INIT;
> +	struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
>   	int status;
>   	const char *backend, *backend_func;
>   
> @@ -433,7 +433,9 @@ static int run_specific_rebase(struct rebase_options *opts)
>   		oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
>   	add_var(&script_snippet, "GIT_QUIET",
>   		opts->flags & REBASE_NO_QUIET ? "" : "t");
> -	add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
> +	sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
> +	add_var(&script_snippet, "git_am_opt", buf.buf);
> +	strbuf_release(&buf);
>   	add_var(&script_snippet, "verbose",
>   		opts->flags & REBASE_VERBOSE ? "t" : "");
>   	add_var(&script_snippet, "diffstat",
> @@ -756,7 +758,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   	struct rebase_options options = {
>   		.type = REBASE_UNSPECIFIED,
>   		.flags = REBASE_NO_QUIET,
> -		.git_am_opt = STRBUF_INIT,
> +		.git_am_opts = ARGV_ARRAY_INIT,
>   		.allow_rerere_autoupdate  = -1,
>   		.allow_empty_message = 1,
>   		.git_format_patch_opt = STRBUF_INIT,
> @@ -777,12 +779,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		ACTION_EDIT_TODO,
>   		ACTION_SHOW_CURRENT_PATCH,
>   	} action = NO_ACTION;
> -	int committer_date_is_author_date = 0;
> -	int ignore_date = 0;
> -	int ignore_whitespace = 0;
>   	const char *gpg_sign = NULL;
> -	int opt_c = -1;
> -	struct string_list whitespace = STRING_LIST_INIT_NODUP;
>   	struct string_list exec = STRING_LIST_INIT_NODUP;
>   	const char *rebase_merges = NULL;
>   	int fork_point = -1;
> @@ -804,15 +801,20 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		{OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
>   			N_("do not show diffstat of what changed upstream"),
>   			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
> -		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
> -			 N_("passed to 'git apply'")),
>   		OPT_BOOL(0, "signoff", &options.signoff,
>   			 N_("add a Signed-off-by: line to each commit")),
> -		OPT_BOOL(0, "committer-date-is-author-date",
> -			 &committer_date_is_author_date,
> -			 N_("passed to 'git am'")),
> -		OPT_BOOL(0, "ignore-date", &ignore_date,
> -			 N_("passed to 'git am'")),
> +		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
> +				  NULL, N_("passed to 'git am'"),
> +				  PARSE_OPT_NOARG),
> +		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
> +				  &options.git_am_opts, NULL,
> +				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
> +		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
> +				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
> +		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
> +				  N_("passed to 'git apply'"), 0),
> +		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
> +				  N_("action"), N_("passed to 'git apply'"), 0),
>   		OPT_BIT('f', "force-rebase", &options.flags,
>   			N_("cherry-pick all commits, even if unchanged"),
>   			REBASE_FORCE),
> @@ -856,10 +858,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		{ OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
>   			N_("GPG-sign commits"),
>   			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
> -		OPT_STRING_LIST(0, "whitespace", &whitespace,
> -				N_("whitespace"), N_("passed to 'git apply'")),
> -		OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
> -			    REBASE_AM),
>   		OPT_BOOL(0, "autostash", &options.autostash,
>   			 N_("automatically stash/stash pop before and after")),
>   		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
> @@ -884,6 +882,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   			 N_("rebase all reachable commits up to the root(s)")),
>   		OPT_END(),
>   	};
> +	int i;
>   
>   	/*
>   	 * NEEDSWORK: Once the builtin rebase has been tested enough
> @@ -1064,22 +1063,17 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		    state_dir_base, cmd_live_rebase, buf.buf);
>   	}
>   
> -	if (!(options.flags & REBASE_NO_QUIET))
> -		strbuf_addstr(&options.git_am_opt, " -q");
> -
> -	if (committer_date_is_author_date) {
> -		strbuf_addstr(&options.git_am_opt,
> -			      " --committer-date-is-author-date");
> -		options.flags |= REBASE_FORCE;
> +	for (i = 0; i < options.git_am_opts.argc; i++) {
> +		const char *option = options.git_am_opts.argv[i];
> +		if (!strcmp(option, "--committer-date-is-author-date") ||
> +		    !strcmp(option, "--ignore-date") ||
> +		    !strcmp(option, "--whitespace=fix") ||
> +		    !strcmp(option, "--whitespace=strip"))
> +			options.flags |= REBASE_FORCE;
>   	}
>   
> -	if (ignore_whitespace)
> -		strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
> -
> -	if (ignore_date) {
> -		strbuf_addstr(&options.git_am_opt, " --ignore-date");
> -		options.flags |= REBASE_FORCE;
> -	}
> +	if (!(options.flags & REBASE_NO_QUIET))
> +		argv_array_push(&options.git_am_opts, "-q");
>   
>   	if (options.keep_empty)
>   		imply_interactive(&options, "--keep-empty");
> @@ -1089,23 +1083,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
>   	}
>   
> -	if (opt_c >= 0)
> -		strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
> -
> -	if (whitespace.nr) {
> -		int i;
> -
> -		for (i = 0; i < whitespace.nr; i++) {
> -			const char *item = whitespace.items[i].string;
> -
> -			strbuf_addf(&options.git_am_opt, " --whitespace=%s",
> -				    item);
> -
> -			if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
> -				options.flags |= REBASE_FORCE;
> -		}
> -	}
> -
>   	if (exec.nr) {
>   		int i;
>   
> @@ -1181,23 +1158,18 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		break;
>   	}
>   
> -	if (options.git_am_opt.len) {
> -		const char *p;
> -
> +	if (options.git_am_opts.argc) {
>   		/* all am options except -q are compatible only with --am */
> -		strbuf_reset(&buf);
> -		strbuf_addbuf(&buf, &options.git_am_opt);
> -		strbuf_addch(&buf, ' ');
> -		while ((p = strstr(buf.buf, " -q ")))
> -			strbuf_splice(&buf, p - buf.buf, 4, " ", 1);
> -		strbuf_trim(&buf);
> +		for (i = options.git_am_opts.argc - 1; i >= 0; i--)
> +			if (strcmp(options.git_am_opts.argv[i], "-q"))
> +				break;
>   
> -		if (is_interactive(&options) && buf.len)
> +		if (is_interactive(&options) && i >= 0)
>   			die(_("error: cannot combine interactive options "
>   			      "(--interactive, --exec, --rebase-merges, "
>   			      "--preserve-merges, --keep-empty, --root + "
>   			      "--onto) with am options (%s)"), buf.buf);
> -		if (options.type == REBASE_MERGE && buf.len)
> +		if (options.type == REBASE_MERGE && i >= 0)
>   			die(_("error: cannot combine merge options (--merge, "
>   			      "--strategy, --strategy-option) with am options "
>   			      "(%s)"), buf.buf);
> @@ -1207,7 +1179,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		if (options.type == REBASE_PRESERVE_MERGES)
>   			die("cannot combine '--signoff' with "
>   			    "'--preserve-merges'");
> -		strbuf_addstr(&options.git_am_opt, " --signoff");
> +		argv_array_push(&options.git_am_opts, "--signoff");
>   		options.flags |= REBASE_FORCE;
>   	}
>   
>