Function am_setup

builtin/am.c:993–1111

* Setup a new am session for applying patches */

 * Setup a new am session for applying patches
 */
static void am_setup(struct am_state *state, enum patch_format patch_format,
			const char **paths, int keep_cr)
{
	struct object_id curr_head;
	const char *str;
	struct strbuf sb = STRBUF_INIT;

	if (!patch_format)
		patch_format = detect_patch_format(paths);

	if (!patch_format) {
		fprintf_ln(stderr, _("Patch format detection failed."));
		die(NULL);
	}

	if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
		die_errno(_("failed to create directory '%s'"), state->dir);
	refs_delete_ref(get_main_ref_store(the_repository), NULL,
			"REBASE_HEAD", NULL, REF_NO_DEREF);

	if (split_mail(state, patch_format, paths, keep_cr) < 0) {
		am_destroy(state);
		die(_("Failed to split patches."));
	}

	if (state->rebasing)
		state->threeway = 1;

	write_state_bool(state, "threeway", state->threeway);
	write_state_bool(state, "quiet", state->quiet);
	write_state_bool(state, "sign", state->signoff);
	write_state_bool(state, "utf8", state->utf8);

	if (state->allow_rerere_autoupdate)
		write_state_bool(state, "rerere-autoupdate",
			 state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);

	switch (state->keep) {
	case KEEP_FALSE:
		str = "f";
		break;
	case KEEP_TRUE:
		str = "t";
		break;
	case KEEP_NON_PATCH:
		str = "b";
		break;
	default:
		BUG("invalid value for state->keep");
	}

	write_state_text(state, "keep", str);
	write_state_bool(state, "messageid", state->message_id);

	switch (state->scissors) {
	case SCISSORS_UNSET:
		str = "";
		break;