diff --git a/builtin/log.c b/builtin/log.c
index f5da29ee2a..890bf0c425 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -945,36 +945,6 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 
 /* format-patch */
 
-static const char *fmt_patch_suffix = ".patch";
-static int numbered = 0;
-static int auto_number = 1;
-
-static char *default_attach = NULL;
-
-static struct string_list extra_hdr = STRING_LIST_INIT_NODUP;
-static struct string_list extra_to = STRING_LIST_INIT_NODUP;
-static struct string_list extra_cc = STRING_LIST_INIT_NODUP;
-
-static void add_header(const char *value)
-{
-	struct string_list_item *item;
-	int len = strlen(value);
-	while (len && value[len - 1] == '\n')
-		len--;
-
-	if (!strncasecmp(value, "to: ", 4)) {
-		item = string_list_append(&extra_to, value + 4);
-		len -= 4;
-	} else if (!strncasecmp(value, "cc: ", 4)) {
-		item = string_list_append(&extra_cc, value + 4);
-		len -= 4;
-	} else {
-		item = string_list_append(&extra_hdr, value);
-	}
-
-	item->string[len] = '\0';
-}
-
 enum cover_setting {
 	COVER_UNSET,
 	COVER_OFF,
@@ -1001,17 +971,61 @@ enum auto_base_setting {
 	AUTO_BASE_WHEN_ABLE
 };
 
-static enum thread_level thread;
-static int do_signoff;
-static enum auto_base_setting auto_base;
-static char *from;
-static const char *signature = git_version_string;
-static char *signature_file;
-static enum cover_setting config_cover_letter;
-static const char *config_output_directory;
-static enum cover_from_description cover_from_description_mode = COVER_FROM_MESSAGE;
-static int show_notes;
-static struct display_notes_opt notes_opt;
+struct format_config {
+	struct log_config log;
+	enum thread_level thread;
+	int do_signoff;
+	enum auto_base_setting auto_base;
+	char *base_commit;
+	char *from;
+	char *signature;
+	char *signature_file;
+	enum cover_setting config_cover_letter;
+	char *config_output_directory;
+	enum cover_from_description cover_from_description_mode;
+	int show_notes;
+	struct display_notes_opt notes_opt;
+	int numbered_cmdline_opt;
+	int numbered;
+	int auto_number;
+	char *default_attach;
+	struct string_list extra_hdr;
+	struct string_list extra_to;
+	struct string_list extra_cc;
+	int keep_subject;
+	int subject_prefix;
+	struct strbuf sprefix;
+	char *fmt_patch_suffix;
+};
+
+static void format_config_init(struct format_config *cfg)
+{
+	memset(cfg, 0, sizeof(*cfg));
+	log_config_init(&cfg->log);
+	cfg->cover_from_description_mode = COVER_FROM_MESSAGE;
+	cfg->auto_number = 1;
+	string_list_init_dup(&cfg->extra_hdr);
+	string_list_init_dup(&cfg->extra_to);
+	string_list_init_dup(&cfg->extra_cc);
+	strbuf_init(&cfg->sprefix, 0);
+	cfg->fmt_patch_suffix = xstrdup(".patch");
+}
+
+static void format_config_release(struct format_config *cfg)
+{
+	log_config_release(&cfg->log);
+	free(cfg->base_commit);
+	free(cfg->from);
+	free(cfg->signature);
+	free(cfg->signature_file);
+	free(cfg->config_output_directory);
+	free(cfg->default_attach);
+	string_list_clear(&cfg->extra_hdr, 0);
+	string_list_clear(&cfg->extra_to, 0);
+	string_list_clear(&cfg->extra_cc, 0);
+	strbuf_release(&cfg->sprefix);
+	free(cfg->fmt_patch_suffix);
+}
 
 static enum cover_from_description parse_cover_from_description(const char *arg)
 {
@@ -1029,27 +1043,51 @@ static enum cover_from_description parse_cover_from_description(const char *arg)
 		die(_("%s: invalid cover from description mode"), arg);
 }
 
+static void add_header(struct format_config *cfg, const char *value)
+{
+	struct string_list_item *item;
+	int len = strlen(value);
+	while (len && value[len - 1] == '\n')
+		len--;
+
+	if (!strncasecmp(value, "to: ", 4)) {
+		item = string_list_append(&cfg->extra_to, value + 4);
+		len -= 4;
+	} else if (!strncasecmp(value, "cc: ", 4)) {
+		item = string_list_append(&cfg->extra_cc, value + 4);
+		len -= 4;
+	} else {
+		item = string_list_append(&cfg->extra_hdr, value);
+	}
+
+	item->string[len] = '\0';
+}
+
 static int git_format_config(const char *var, const char *value,
 			     const struct config_context *ctx, void *cb)
 {
+	struct format_config *cfg = cb;
+
 	if (!strcmp(var, "format.headers")) {
 		if (!value)
 			die(_("format.headers without value"));
-		add_header(value);
+		add_header(cfg, value);
 		return 0;
 	}
-	if (!strcmp(var, "format.suffix"))
-		return git_config_string(&fmt_patch_suffix, var, value);
+	if (!strcmp(var, "format.suffix")) {
+		FREE_AND_NULL(cfg->fmt_patch_suffix);
+		return git_config_string((const char **) &cfg->fmt_patch_suffix, var, value);
+	}
 	if (!strcmp(var, "format.to")) {
 		if (!value)
 			return config_error_nonbool(var);
-		string_list_append(&extra_to, value);
+		string_list_append(&cfg->extra_to, value);
 		return 0;
 	}
 	if (!strcmp(var, "format.cc")) {
 		if (!value)
 			return config_error_nonbool(var);
-		string_list_append(&extra_cc, value);
+		string_list_append(&cfg->extra_cc, value);
 		return 0;
 	}
 	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
@@ -1058,69 +1096,76 @@ static int git_format_config(const char *var, const char *value,
 	}
 	if (!strcmp(var, "format.numbered")) {
 		if (value && !strcasecmp(value, "auto")) {
-			auto_number = 1;
+			cfg->auto_number = 1;
 			return 0;
 		}
-		numbered = git_config_bool(var, value);
-		auto_number = auto_number && numbered;
+		cfg->numbered = git_config_bool(var, value);
+		cfg->auto_number = cfg->auto_number && cfg->numbered;
 		return 0;
 	}
 	if (!strcmp(var, "format.attach")) {
-		if (value && *value)
-			default_attach = xstrdup(value);
-		else if (value && !*value)
-			FREE_AND_NULL(default_attach);
-		else
-			default_attach = xstrdup(git_version_string);
+		if (value && *value) {
+			FREE_AND_NULL(cfg->default_attach);
+			cfg->default_attach = xstrdup(value);
+		} else if (value && !*value) {
+			FREE_AND_NULL(cfg->default_attach);
+		} else {
+			FREE_AND_NULL(cfg->default_attach);
+			cfg->default_attach = xstrdup(git_version_string);
+		}
 		return 0;
 	}
 	if (!strcmp(var, "format.thread")) {
 		if (value && !strcasecmp(value, "deep")) {
-			thread = THREAD_DEEP;
+			cfg->thread = THREAD_DEEP;
 			return 0;
 		}
 		if (value && !strcasecmp(value, "shallow")) {
-			thread = THREAD_SHALLOW;
+			cfg->thread = THREAD_SHALLOW;
 			return 0;
 		}
-		thread = git_config_bool(var, value) ? THREAD_SHALLOW : THREAD_UNSET;
+		cfg->thread = git_config_bool(var, value) ? THREAD_SHALLOW : THREAD_UNSET;
 		return 0;
 	}
 	if (!strcmp(var, "format.signoff")) {
-		do_signoff = git_config_bool(var, value);
+		cfg->do_signoff = git_config_bool(var, value);
 		return 0;
 	}
-	if (!strcmp(var, "format.signature"))
-		return git_config_string(&signature, var, value);
-	if (!strcmp(var, "format.signaturefile"))
-		return git_config_pathname(&signature_file, var, value);
+	if (!strcmp(var, "format.signature")) {
+		FREE_AND_NULL(cfg->signature);
+		return git_config_string((const char **) &cfg->signature, var, value);
+	}
+	if (!strcmp(var, "format.signaturefile")) {
+		FREE_AND_NULL(cfg->signature_file);
+		return git_config_pathname(&cfg->signature_file, var, value);
+	}
 	if (!strcmp(var, "format.coverletter")) {
 		if (value && !strcasecmp(value, "auto")) {
-			config_cover_letter = COVER_AUTO;
+			cfg->config_cover_letter = COVER_AUTO;
 			return 0;
 		}
-		config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
+		cfg->config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
 		return 0;
 	}
-	if (!strcmp(var, "format.outputdirectory"))
-		return git_config_string(&config_output_directory, var, value);
+	if (!strcmp(var, "format.outputdirectory")) {
+		FREE_AND_NULL(cfg->config_output_directory);
+		return git_config_string((const char **) &cfg->config_output_directory, var, value);
+	}
 	if (!strcmp(var, "format.useautobase")) {
 		if (value && !strcasecmp(value, "whenAble")) {
-			auto_base = AUTO_BASE_WHEN_ABLE;
+			cfg->auto_base = AUTO_BASE_WHEN_ABLE;
 			return 0;
 		}
-		auto_base = git_config_bool(var, value) ? AUTO_BASE_ALWAYS : AUTO_BASE_NEVER;
+		cfg->auto_base = git_config_bool(var, value) ? AUTO_BASE_ALWAYS : AUTO_BASE_NEVER;
 		return 0;
 	}
 	if (!strcmp(var, "format.from")) {
 		int b = git_parse_maybe_bool(value);
-		free(from);
+		FREE_AND_NULL(cfg->from);
 		if (b < 0)
-			from = xstrdup(value);
+			cfg->from = xstrdup(value);
 		else if (b)
-			from = xstrdup(git_committer_info(IDENT_NO_DATE));
-		else
-			from = NULL;
+			cfg->from = xstrdup(git_committer_info(IDENT_NO_DATE));
 		return 0;
 	}
 	if (!strcmp(var, "format.forceinbodyfrom")) {
@@ -1130,15 +1175,15 @@ static int git_format_config(const char *var, const char *value,
 	if (!strcmp(var, "format.notes")) {
 		int b = git_parse_maybe_bool(value);
 		if (b < 0)
-			enable_ref_display_notes(&notes_opt, &show_notes, value);
+			enable_ref_display_notes(&cfg->notes_opt, &cfg->show_notes, value);
 		else if (b)
-			enable_default_display_notes(&notes_opt, &show_notes);
+			enable_default_display_notes(&cfg->notes_opt, &cfg->show_notes);
 		else
-			disable_display_notes(&notes_opt, &show_notes);
+			disable_display_notes(&cfg->notes_opt, &cfg->show_notes);
 		return 0;
 	}
 	if (!strcmp(var, "format.coverfromdescription")) {
-		cover_from_description_mode = parse_cover_from_description(value);
+		cfg->cover_from_description_mode = parse_cover_from_description(value);
 		return 0;
 	}
 	if (!strcmp(var, "format.mboxrd")) {
@@ -1159,7 +1204,7 @@ static int git_format_config(const char *var, const char *value,
 	if (!strcmp(var, "diff.noprefix"))
 		return 0;
 
-	return git_log_config(var, value, ctx, cb);
+	return git_log_config(var, value, ctx, &cfg->log);
 }
 
 static const char *output_directory = NULL;
@@ -1247,7 +1292,7 @@ static void gen_message_id(struct rev_info *info, char *base)
 	info->message_id = strbuf_detach(&buf, NULL);
 }
 
-static void print_signature(FILE *file)
+static void print_signature(const char *signature, FILE *file)
 {
 	if (!signature || !*signature)
 		return;
@@ -1317,14 +1362,15 @@ static void prepare_cover_text(struct pretty_print_context *pp,
 			       const char *branch_name,
 			       struct strbuf *sb,
 			       const char *encoding,
-			       int need_8bit_cte)
+			       int need_8bit_cte,
+			       const struct format_config *cfg)
 {
 	const char *subject = "*** SUBJECT HERE ***";
 	const char *body = "*** BLURB HERE ***";
 	struct strbuf description_sb = STRBUF_INIT;
 	struct strbuf subject_sb = STRBUF_INIT;
 
-	if (cover_from_description_mode == COVER_FROM_NONE)
+	if (cfg->cover_from_description_mode == COVER_FROM_NONE)
 		goto do_pp;
 
 	if (description_file && *description_file)
@@ -1334,13 +1380,13 @@ static void prepare_cover_text(struct pretty_print_context *pp,
 	if (!description_sb.len)
 		goto do_pp;
 
-	if (cover_from_description_mode == COVER_FROM_SUBJECT ||
-			cover_from_description_mode == COVER_FROM_AUTO)
+	if (cfg->cover_from_description_mode == COVER_FROM_SUBJECT ||
+	    cfg->cover_from_description_mode == COVER_FROM_AUTO)
 		body = format_subject(&subject_sb, description_sb.buf, " ");
 
-	if (cover_from_description_mode == COVER_FROM_MESSAGE ||
-			(cover_from_description_mode == COVER_FROM_AUTO &&
-			 subject_sb.len > COVER_FROM_AUTO_MAX_SUBJECT_LEN))
+	if (cfg->cover_from_description_mode == COVER_FROM_MESSAGE ||
+	    (cfg->cover_from_description_mode == COVER_FROM_AUTO &&
+	     subject_sb.len > COVER_FROM_AUTO_MAX_SUBJECT_LEN))
 		body = description_sb.buf;
 	else
 		subject = subject_sb.buf;
@@ -1377,7 +1423,8 @@ static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 			      int nr, struct commit **list,
 			      const char *description_file,
 			      const char *branch_name,
-			      int quiet)
+			      int quiet,
+			      const struct format_config *cfg)
 {
 	const char *committer;
 	struct shortlog log;
@@ -1416,7 +1463,7 @@ static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 	pp.encode_email_headers = rev->encode_email_headers;
 	pp_user_info(&pp, NULL, &sb, committer, encoding);
 	prepare_cover_text(&pp, description_file, branch_name, &sb,
-			   encoding, need_8bit_cte);
+			   encoding, need_8bit_cte, cfg);
 	fprintf(rev->diffopt.file, "%s\n", sb.buf);
 
 	free(pp.after_subject);
@@ -1517,29 +1564,30 @@ static const char * const builtin_format_patch_usage[] = {
 	NULL
 };
 
-static int keep_subject = 0;
+struct keep_callback_data {
+	struct format_config *cfg;
+	struct rev_info *revs;
+};
 
 static int keep_callback(const struct option *opt, const char *arg, int unset)
 {
+	struct keep_callback_data *data = opt->value;
 	BUG_ON_OPT_NEG(unset);
 	BUG_ON_OPT_ARG(arg);
-	((struct rev_info *)opt->value)->total = -1;
-	keep_subject = 1;
+	data->revs->total = -1;
+	data->cfg->keep_subject = 1;
 	return 0;
 }
 
-static int subject_prefix = 0;
-
 static int subject_prefix_callback(const struct option *opt, const char *arg,
 			    int unset)
 {
-	struct strbuf *sprefix;
+	struct format_config *cfg = opt->value;
 
 	BUG_ON_OPT_NEG(unset);
-	sprefix = opt->value;
-	subject_prefix = 1;
-	strbuf_reset(sprefix);
-	strbuf_addstr(sprefix, arg);
+	cfg->subject_prefix = 1;
+	strbuf_reset(&cfg->sprefix);
+	strbuf_addstr(&cfg->sprefix, arg);
 	return 0;
 }
 
@@ -1556,15 +1604,14 @@ static int rfc_callback(const struct option *opt, const char *arg,
 	return 0;
 }
 
-static int numbered_cmdline_opt = 0;
-
 static int numbered_callback(const struct option *opt, const char *arg,
 			     int unset)
 {
+	struct format_config *cfg = opt->value;
 	BUG_ON_OPT_ARG(arg);
-	*(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
+	cfg->numbered = cfg->numbered_cmdline_opt = unset ? 0 : 1;
 	if (unset)
-		auto_number =  0;
+		cfg->auto_number =  0;
 	return 0;
 }
 
@@ -1588,13 +1635,14 @@ static int output_directory_callback(const struct option *opt, const char *arg,
 
 static int thread_callback(const struct option *opt, const char *arg, int unset)
 {
-	enum thread_level *thread = (enum thread_level *)opt->value;
+	struct format_config *cfg = opt->value;
+
 	if (unset)
-		*thread = THREAD_UNSET;
+		cfg->thread = THREAD_UNSET;
 	else if (!arg || !strcmp(arg, "shallow"))
-		*thread = THREAD_SHALLOW;
+		cfg->thread = THREAD_SHALLOW;
 	else if (!strcmp(arg, "deep"))
-		*thread = THREAD_DEEP;
+		cfg->thread = THREAD_DEEP;
 	/*
 	 * Please update _git_formatpatch() in git-completion.bash
 	 * when you add new options.
@@ -1630,15 +1678,17 @@ static int inline_callback(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
-static int header_callback(const struct option *opt UNUSED, const char *arg,
+static int header_callback(const struct option *opt, const char *arg,
 			   int unset)
 {
+	struct format_config *cfg = opt->value;
+
 	if (unset) {
-		string_list_clear(&extra_hdr, 0);
-		string_list_clear(&extra_to, 0);
-		string_list_clear(&extra_cc, 0);
+		string_list_clear(&cfg->extra_hdr, 0);
+		string_list_clear(&cfg->extra_to, 0);
+		string_list_clear(&cfg->extra_cc, 0);
 	} else {
-		add_header(arg);
+		add_header(cfg, arg);
 	}
 	return 0;
 }
@@ -1660,17 +1710,17 @@ static int from_callback(const struct option *opt, const char *arg, int unset)
 
 static int base_callback(const struct option *opt, const char *arg, int unset)
 {
-	const char **base_commit = opt->value;
+	struct format_config *cfg = opt->value;
 
 	if (unset) {
-		auto_base = AUTO_BASE_NEVER;
-		*base_commit = NULL;
+		cfg->auto_base = AUTO_BASE_NEVER;
+		FREE_AND_NULL(cfg->base_commit);
 	} else if (!strcmp(arg, "auto")) {
-		auto_base = AUTO_BASE_ALWAYS;
-		*base_commit = NULL;
+		cfg->auto_base = AUTO_BASE_ALWAYS;
+		FREE_AND_NULL(cfg->base_commit);
 	} else {
-		auto_base = AUTO_BASE_NEVER;
-		*base_commit = arg;
+		cfg->auto_base = AUTO_BASE_NEVER;
+		cfg->base_commit = xstrdup(arg);
 	}
 	return 0;
 }
@@ -1681,7 +1731,7 @@ struct base_tree_info {
 	struct object_id *patch_id;
 };
 
-static struct commit *get_base_commit(const char *base_commit,
+static struct commit *get_base_commit(const struct format_config *cfg,
 				      struct commit **list,
 				      int total)
 {
@@ -1689,9 +1739,9 @@ static struct commit *get_base_commit(const char *base_commit,
 	struct commit **rev;
 	int i = 0, rev_nr = 0, auto_select, die_on_failure, ret;
 
-	switch (auto_base) {
+	switch (cfg->auto_base) {
 	case AUTO_BASE_NEVER:
-		if (base_commit) {
+		if (cfg->base_commit) {
 			auto_select = 0;
 			die_on_failure = 1;
 		} else {
@@ -1701,11 +1751,11 @@ static struct commit *get_base_commit(const char *base_commit,
 		break;
 	case AUTO_BASE_ALWAYS:
 	case AUTO_BASE_WHEN_ABLE:
-		if (base_commit) {
+		if (cfg->base_commit) {
 			BUG("requested automatic base selection but a commit was provided");
 		} else {
 			auto_select = 1;
-			die_on_failure = auto_base == AUTO_BASE_ALWAYS;
+			die_on_failure = cfg->auto_base == AUTO_BASE_ALWAYS;
 		}
 		break;
 	default:
@@ -1713,9 +1763,9 @@ static struct commit *get_base_commit(const char *base_commit,
 	}
 
 	if (!auto_select) {
-		base = lookup_commit_reference_by_name(base_commit);
+		base = lookup_commit_reference_by_name(cfg->base_commit);
 		if (!base)
-			die(_("unknown commit %s"), base_commit);
+			die(_("unknown commit %s"), cfg->base_commit);
 	} else {
 		struct branch *curr_branch = branch_get(NULL);
 		const char *upstream = branch_get_upstream(curr_branch, NULL);
@@ -1933,7 +1983,7 @@ static void infer_range_diff_ranges(struct strbuf *r1,
 
 int cmd_format_patch(int argc, const char **argv, const char *prefix)
 {
-	struct log_config cfg;
+	struct format_config cfg;
 	struct commit *commit;
 	struct commit **list = NULL;
 	struct rev_info rev;
@@ -1958,7 +2008,6 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	char *cover_from_description_arg = NULL;
 	char *description_file = NULL;
 	char *branch_name = NULL;
-	char *base_commit = NULL;
 	struct base_tree_info bases;
 	struct commit *base;
 	int show_progress = 0;
@@ -1969,18 +2018,24 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	struct strbuf rdiff1 = STRBUF_INIT;
 	struct strbuf rdiff2 = STRBUF_INIT;
 	struct strbuf rdiff_title = STRBUF_INIT;
-	struct strbuf sprefix = STRBUF_INIT;
 	const char *rfc = NULL;
 	int creation_factor = -1;
+	const char *signature = git_version_string;
+	const char *signature_file_arg = NULL;
+	struct keep_callback_data keep_callback_data = {
+		.cfg = &cfg,
+		.revs = &rev,
+	};
+	const char *fmt_patch_suffix = NULL;
 
 	const struct option builtin_format_patch_options[] = {
-		OPT_CALLBACK_F('n', "numbered", &numbered, NULL,
+		OPT_CALLBACK_F('n', "numbered", &cfg, NULL,
 			    N_("use [PATCH n/m] even with a single patch"),
 			    PARSE_OPT_NOARG, numbered_callback),
-		OPT_CALLBACK_F('N', "no-numbered", &numbered, NULL,
+		OPT_CALLBACK_F('N', "no-numbered", &cfg, NULL,
 			    N_("use [PATCH] even with multiple patches"),
 			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback),
-		OPT_BOOL('s', "signoff", &do_signoff, N_("add a Signed-off-by trailer")),
+		OPT_BOOL('s', "signoff", &cfg.do_signoff, N_("add a Signed-off-by trailer")),
 		OPT_BOOL(0, "stdout", &use_stdout,
 			    N_("print patches to standard out")),
 		OPT_BOOL(0, "cover-letter", &cover_letter,
@@ -1993,7 +2048,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			    N_("start numbering patches at <n> instead of 1")),
 		OPT_STRING('v', "reroll-count", &reroll_count, N_("reroll-count"),
 			    N_("mark the series as Nth re-roll")),
-		OPT_INTEGER(0, "filename-max-length", &cfg.fmt_patch_name_max,
+		OPT_INTEGER(0, "filename-max-length", &cfg.log.fmt_patch_name_max,
 			    N_("max length of output filename")),
 		OPT_CALLBACK_F(0, "rfc", &rfc, N_("rfc"),
 			       N_("add <rfc> (default 'RFC') before 'PATCH'"),
@@ -2003,13 +2058,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			    N_("generate parts of a cover letter based on a branch's description")),
 		OPT_FILENAME(0, "description-file", &description_file,
 			     N_("use branch description from file")),
-		OPT_CALLBACK_F(0, "subject-prefix", &sprefix, N_("prefix"),
+		OPT_CALLBACK_F(0, "subject-prefix", &cfg, N_("prefix"),
 			    N_("use [<prefix>] instead of [PATCH]"),
 			    PARSE_OPT_NONEG, subject_prefix_callback),
 		OPT_CALLBACK_F('o', "output-directory", &output_directory,
 			    N_("dir"), N_("store resulting files in <dir>"),
 			    PARSE_OPT_NONEG, output_directory_callback),
-		OPT_CALLBACK_F('k', "keep-subject", &rev, NULL,
+		OPT_CALLBACK_F('k', "keep-subject", &keep_callback_data, NULL,
 			    N_("don't strip/add [PATCH]"),
 			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback),
 		OPT_BOOL(0, "no-binary", &no_binary_diff,
@@ -2022,11 +2077,11 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			      N_("show patch format instead of default (patch + stat)"),
 			      1, PARSE_OPT_NONEG),
 		OPT_GROUP(N_("Messaging")),
-		OPT_CALLBACK(0, "add-header", NULL, N_("header"),
+		OPT_CALLBACK(0, "add-header", &cfg, N_("header"),
 			    N_("add email header"), header_callback),
-		OPT_STRING_LIST(0, "to", &extra_to, N_("email"), N_("add To: header")),
-		OPT_STRING_LIST(0, "cc", &extra_cc, N_("email"), N_("add Cc: header")),
-		OPT_CALLBACK_F(0, "from", &from, N_("ident"),
+		OPT_STRING_LIST(0, "to", &cfg.extra_to, N_("email"), N_("add To: header")),
+		OPT_STRING_LIST(0, "cc", &cfg.extra_cc, N_("email"), N_("add Cc: header")),
+		OPT_CALLBACK_F(0, "from", &cfg.from, N_("ident"),
 			    N_("set From address to <ident> (or committer ident if absent)"),
 			    PARSE_OPT_OPTARG, from_callback),
 		OPT_STRING(0, "in-reply-to", &in_reply_to, N_("message-id"),
@@ -2038,15 +2093,15 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			    N_("inline the patch"),
 			    PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 			    inline_callback),
-		OPT_CALLBACK_F(0, "thread", &thread, N_("style"),
+		OPT_CALLBACK_F(0, "thread", &cfg, N_("style"),
 			    N_("enable message threading, styles: shallow, deep"),
 			    PARSE_OPT_OPTARG, thread_callback),
 		OPT_STRING(0, "signature", &signature, N_("signature"),
 			    N_("add a signature")),
-		OPT_CALLBACK_F(0, "base", &base_commit, N_("base-commit"),
+		OPT_CALLBACK_F(0, "base", &cfg, N_("base-commit"),
 			       N_("add prerequisite tree info to the patch series"),
 			       0, base_callback),
-		OPT_FILENAME(0, "signature-file", &signature_file,
+		OPT_FILENAME(0, "signature-file", &signature_file_arg,
 				N_("add a signature from a file")),
 		OPT__QUIET(&quiet, N_("don't print the patch filenames")),
 		OPT_BOOL(0, "progress", &show_progress,
@@ -2063,21 +2118,17 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	extra_hdr.strdup_strings = 1;
-	extra_to.strdup_strings = 1;
-	extra_cc.strdup_strings = 1;
-
-	log_config_init(&cfg);
+	format_config_init(&cfg);
 	init_diff_ui_defaults();
-	init_display_notes(&notes_opt);
+	init_display_notes(&cfg.notes_opt);
 	git_config(git_format_config, &cfg);
 	repo_init_revisions(the_repository, &rev, prefix);
 	git_config(grep_config, &rev.grep_filter);
 
-	rev.show_notes = show_notes;
-	memcpy(&rev.notes_opt, &notes_opt, sizeof(notes_opt));
+	rev.show_notes = cfg.show_notes;
+	memcpy(&rev.notes_opt, &cfg.notes_opt, sizeof(cfg.notes_opt));
 	rev.commit_format = CMIT_FMT_EMAIL;
-	rev.encode_email_headers = cfg.default_encode_email_headers;
+	rev.encode_email_headers = cfg.log.default_encode_email_headers;
 	rev.expand_tabs_in_log_default = 0;
 	rev.verbose_header = 1;
 	rev.diff = 1;
@@ -2088,12 +2139,12 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	s_r_opt.def = "HEAD";
 	s_r_opt.revarg_opt = REVARG_COMMITTISH;
 
-	strbuf_addstr(&sprefix, cfg.fmt_patch_subject_prefix);
+	strbuf_addstr(&cfg.sprefix, cfg.log.fmt_patch_subject_prefix);
 	if (format_no_prefix)
 		diff_set_noprefix(&rev.diffopt);
 
-	if (default_attach) {
-		rev.mime_boundary = default_attach;
+	if (cfg.default_attach) {
+		rev.mime_boundary = cfg.default_attach;
 		rev.no_inline = 1;
 	}
 
@@ -2109,60 +2160,63 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 
 	rev.force_in_body_from = force_in_body_from;
 
+	if (!fmt_patch_suffix)
+		fmt_patch_suffix = cfg.fmt_patch_suffix;
+
 	/* Make sure "0000-$sub.patch" gives non-negative length for $sub */
-	if (cfg.fmt_patch_name_max <= strlen("0000-") + strlen(fmt_patch_suffix))
-		cfg.fmt_patch_name_max = strlen("0000-") + strlen(fmt_patch_suffix);
+	if (cfg.log.fmt_patch_name_max <= strlen("0000-") + strlen(fmt_patch_suffix))
+		cfg.log.fmt_patch_name_max = strlen("0000-") + strlen(fmt_patch_suffix);
 
 	if (cover_from_description_arg)
-		cover_from_description_mode = parse_cover_from_description(cover_from_description_arg);
+		cfg.cover_from_description_mode = parse_cover_from_description(cover_from_description_arg);
 
 	if (rfc && rfc[0]) {
-		subject_prefix = 1;
+		cfg.subject_prefix = 1;
 		if (rfc[0] == '-')
-			strbuf_addf(&sprefix, " %s", rfc + 1);
+			strbuf_addf(&cfg.sprefix, " %s", rfc + 1);
 		else
-			strbuf_insertf(&sprefix, 0, "%s ", rfc);
+			strbuf_insertf(&cfg.sprefix, 0, "%s ", rfc);
 	}
 
 	if (reroll_count) {
-		strbuf_addf(&sprefix, " v%s", reroll_count);
+		strbuf_addf(&cfg.sprefix, " v%s", reroll_count);
 		rev.reroll_count = reroll_count;
 	}
 
-	rev.subject_prefix = sprefix.buf;
+	rev.subject_prefix = cfg.sprefix.buf;
 
-	for (i = 0; i < extra_hdr.nr; i++) {
-		strbuf_addstr(&buf, extra_hdr.items[i].string);
+	for (i = 0; i < cfg.extra_hdr.nr; i++) {
+		strbuf_addstr(&buf, cfg.extra_hdr.items[i].string);
 		strbuf_addch(&buf, '\n');
 	}
 
-	if (extra_to.nr)
+	if (cfg.extra_to.nr)
 		strbuf_addstr(&buf, "To: ");
-	for (i = 0; i < extra_to.nr; i++) {
+	for (i = 0; i < cfg.extra_to.nr; i++) {
 		if (i)
 			strbuf_addstr(&buf, "    ");
-		strbuf_addstr(&buf, extra_to.items[i].string);
-		if (i + 1 < extra_to.nr)
+		strbuf_addstr(&buf, cfg.extra_to.items[i].string);
+		if (i + 1 < cfg.extra_to.nr)
 			strbuf_addch(&buf, ',');
 		strbuf_addch(&buf, '\n');
 	}
 
-	if (extra_cc.nr)
+	if (cfg.extra_cc.nr)
 		strbuf_addstr(&buf, "Cc: ");
-	for (i = 0; i < extra_cc.nr; i++) {
+	for (i = 0; i < cfg.extra_cc.nr; i++) {
 		if (i)
 			strbuf_addstr(&buf, "    ");
-		strbuf_addstr(&buf, extra_cc.items[i].string);
-		if (i + 1 < extra_cc.nr)
+		strbuf_addstr(&buf, cfg.extra_cc.items[i].string);
+		if (i + 1 < cfg.extra_cc.nr)
 			strbuf_addch(&buf, ',');
 		strbuf_addch(&buf, '\n');
 	}
 
 	rev.extra_headers = to_free = strbuf_detach(&buf, NULL);
 
-	if (from) {
-		if (split_ident_line(&rev.from_ident, from, strlen(from)))
-			die(_("invalid ident line: %s"), from);
+	if (cfg.from) {
+		if (split_ident_line(&rev.from_ident, cfg.from, strlen(cfg.from)))
+			die(_("invalid ident line: %s"), cfg.from);
 	}
 
 	if (start_number < 0)
@@ -2173,14 +2227,14 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	 * and it would conflict with --keep-subject (-k) from the
 	 * command line, reset "numbered".
 	 */
-	if (numbered && keep_subject && !numbered_cmdline_opt)
-		numbered = 0;
+	if (cfg.numbered && cfg.keep_subject && !cfg.numbered_cmdline_opt)
+		cfg.numbered = 0;
 
-	if (numbered && keep_subject)
+	if (cfg.numbered && cfg.keep_subject)
 		die(_("options '%s' and '%s' cannot be used together"), "-n", "-k");
-	if (keep_subject && subject_prefix)
+	if (cfg.keep_subject && cfg.subject_prefix)
 		die(_("options '%s' and '%s' cannot be used together"), "--subject-prefix/--rfc", "-k");
-	rev.preserve_subject = keep_subject;
+	rev.preserve_subject = cfg.keep_subject;
 
 	argc = setup_revisions(argc, argv, &rev, &s_r_opt);
 	if (argc > 1)
@@ -2207,7 +2261,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.always_show_header = 1;
 
 	rev.zero_commit = zero_commit;
-	rev.patch_name_max = cfg.fmt_patch_name_max;
+	rev.patch_name_max = cfg.log.fmt_patch_name_max;
 
 	if (!rev.diffopt.flags.text && !no_binary_diff)
 		rev.diffopt.flags.binary = 1;
@@ -2228,7 +2282,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		int saved;
 
 		if (!output_directory)
-			output_directory = config_output_directory;
+			output_directory = cfg.config_output_directory;
 		output_directory = set_outdir(prefix, output_directory);
 
 		if (rev.diffopt.use_color != GIT_COLOR_ALWAYS)
@@ -2326,14 +2380,14 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		goto done;
 	total = nr;
 	if (cover_letter == -1) {
-		if (config_cover_letter == COVER_AUTO)
+		if (cfg.config_cover_letter == COVER_AUTO)
 			cover_letter = (total > 1);
 		else
-			cover_letter = (config_cover_letter == COVER_ON);
+			cover_letter = (cfg.config_cover_letter == COVER_ON);
 	}
-	if (!keep_subject && auto_number && (total > 1 || cover_letter))
-		numbered = 1;
-	if (numbered)
+	if (!cfg.keep_subject && cfg.auto_number && (total > 1 || cover_letter))
+		cfg.numbered = 1;
+	if (cfg.numbered)
 		rev.total = total + start_number - 1;
 
 	if (idiff_prev.nr) {
@@ -2365,27 +2419,40 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 					     _("Range-diff against v%d:"));
 	}
 
+	/*
+	 * The order of precedence is:
+	 *
+	 *   1. The `--signature` and `--no-signature` options.
+	 *   2. The `--signature-file` option.
+	 *   3. The `format.signature` config.
+	 *   4. The `format.signatureFile` config.
+	 *   5. Default `git_version_string`.
+	 */
 	if (!signature) {
 		; /* --no-signature inhibits all signatures */
 	} else if (signature && signature != git_version_string) {
 		; /* non-default signature already set */
-	} else if (signature_file) {
+	} else if (signature_file_arg || (cfg.signature_file && !cfg.signature)) {
 		struct strbuf buf = STRBUF_INIT;
+		const char *signature_file = signature_file_arg ?
+			signature_file_arg : cfg.signature_file;
 
 		if (strbuf_read_file(&buf, signature_file, 128) < 0)
 			die_errno(_("unable to read signature file '%s'"), signature_file);
 		signature = strbuf_detach(&buf, NULL);
+	} else if (cfg.signature) {
+		signature = cfg.signature;
 	}
 
 	memset(&bases, 0, sizeof(bases));
-	base = get_base_commit(base_commit, list, nr);
+	base = get_base_commit(&cfg, list, nr);
 	if (base) {
 		reset_revision_walk();
 		clear_object_flags(UNINTERESTING);
 		prepare_bases(&bases, base, list, nr);
 	}
 
-	if (in_reply_to || thread || cover_letter) {
+	if (in_reply_to || cfg.thread || cover_letter) {
 		rev.ref_message_ids = xmalloc(sizeof(*rev.ref_message_ids));
 		string_list_init_dup(rev.ref_message_ids);
 	}
@@ -2396,19 +2463,19 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.numbered_files = just_numbers;
 	rev.patch_suffix = fmt_patch_suffix;
 	if (cover_letter) {
-		if (thread)
+		if (cfg.thread)
 			gen_message_id(&rev, "cover");
 		make_cover_letter(&rev, !!output_directory,
-				  origin, nr, list, description_file, branch_name, quiet);
+				  origin, nr, list, description_file, branch_name, quiet, &cfg);
 		print_bases(&bases, rev.diffopt.file);
-		print_signature(rev.diffopt.file);
+		print_signature(signature, rev.diffopt.file);
 		total++;
 		start_number--;
 		/* interdiff/range-diff in cover-letter; omit from patches */
 		rev.idiff_oid1 = NULL;
 		rev.rdiff1 = NULL;
 	}
-	rev.add_signoff = do_signoff;
+	rev.add_signoff = cfg.do_signoff;
 
 	if (show_progress)
 		progress = start_delayed_progress(_("Generating patches"), total);
@@ -2418,7 +2485,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		commit = list[nr];
 		rev.nr = total - nr + (start_number - 1);
 		/* Make the second and subsequent mails replies to the first */
-		if (thread) {
+		if (cfg.thread) {
 			/* Have we already had a message ID? */
 			if (rev.message_id) {
 				/*
@@ -2442,7 +2509,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 				 * letter is a reply to the
 				 * --in-reply-to, if specified.
 				 */
-				if (thread == THREAD_SHALLOW
+				if (cfg.thread == THREAD_SHALLOW
 				    && rev.ref_message_ids->nr > 0
 				    && (!cover_letter || rev.nr > 1))
 					free(rev.message_id);
@@ -2475,7 +2542,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 				       mime_boundary_leader,
 				       rev.mime_boundary);
 			else
-				print_signature(rev.diffopt.file);
+				print_signature(signature, rev.diffopt.file);
 		}
 		if (output_directory)
 			fclose(rev.diffopt.file);
@@ -2483,9 +2550,6 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	stop_progress(&progress);
 	free(list);
 	free(branch_name);
-	string_list_clear(&extra_to, 0);
-	string_list_clear(&extra_cc, 0);
-	string_list_clear(&extra_hdr, 0);
 	if (ignore_if_in_upstream)
 		free_patch_ids(&ids);
 
@@ -2495,14 +2559,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	strbuf_release(&rdiff1);
 	strbuf_release(&rdiff2);
 	strbuf_release(&rdiff_title);
-	strbuf_release(&sprefix);
 	free(to_free);
 	free(rev.message_id);
 	if (rev.ref_message_ids)
 		string_list_clear(rev.ref_message_ids, 0);
 	free(rev.ref_message_ids);
 	release_revisions(&rev);
-	log_config_release(&cfg);
+	format_config_release(&cfg);
 	return 0;
 }
 
