update-index: there are only two possible line terminations

The program by default reads LF terminated lines, with an option to
use NUL terminated records.  Instead of pretending that there can be
other useful values for line_termination, use a boolean variable,
nul_term_line, to tell if NUL terminated records are used, and
switch between strbuf_getline_{lf,nul} based on it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/update-index.c

@@ -468,12 +468,14 @@ static void update_one(const char *path)
 	report("add '%s'", path);
 }
 
-static void read_index_info(int line_termination)
+static void read_index_info(int nul_term_line)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf uq = STRBUF_INIT;
+	strbuf_getline_fn getline_fn;
 
-	while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
+	getline_fn = nul_term_line ? strbuf_getline_nul : strbuf_getline_lf;
+	while (getline_fn(&buf, stdin) != EOF) {
 		char *ptr, *tab;
 		char *path_name;
 		unsigned char sha1[20];
@@ -522,7 +524,7 @@ static void read_index_info(int line_termination)
 			goto bad_line;
 
 		path_name = ptr;
-		if (line_termination && path_name[0] == '"') {
+		if (!nul_term_line && path_name[0] == '"') {
 			strbuf_reset(&uq);
 			if (unquote_c_style(&uq, path_name, NULL)) {
 				die("git update-index: bad quoting of path name");
@@ -844,12 +846,12 @@ static int cacheinfo_callback(struct parse_opt_ctx_t *ctx,
 static int stdin_cacheinfo_callback(struct parse_opt_ctx_t *ctx,
 			      const struct option *opt, int unset)
 {
-	int *line_termination = opt->value;
+	int *nul_term_line = opt->value;
 
 	if (ctx->argc != 1)
 		return error("option '%s' must be the last argument", opt->long_name);
 	allow_add = allow_replace = allow_remove = 1;
-	read_index_info(*line_termination);
+	read_index_info(*nul_term_line);
 	return 0;
 }
 
@@ -901,7 +903,7 @@ static int reupdate_callback(struct parse_opt_ctx_t *ctx,
 
 int cmd_update_index(int argc, const char **argv, const char *prefix)
 {
-	int newfd, entries, has_errors = 0, line_termination = '\n';
+	int newfd, entries, has_errors = 0, nul_term_line = 0;
 	int untracked_cache = -1;
 	int read_from_stdin = 0;
 	int prefix_length = prefix ? strlen(prefix) : 0;
@@ -912,6 +914,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 	int split_index = -1;
 	struct lock_file *lock_file;
 	struct parse_opt_ctx_t ctx;
+	strbuf_getline_fn getline_fn;
 	int parseopt_state = PARSE_OPT_UNKNOWN;
 	struct option options[] = {
 		OPT_BIT('q', NULL, &refresh_args.flags,
@@ -963,13 +966,13 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			N_("add to index only; do not add content to object database"), 1),
 		OPT_SET_INT(0, "force-remove", &force_remove,
 			N_("remove named paths even if present in worktree"), 1),
-		OPT_SET_INT('z', NULL, &line_termination,
-			N_("with --stdin: input lines are terminated by null bytes"), '\0'),
+		OPT_BOOL('z', NULL, &nul_term_line,
+			 N_("with --stdin: input lines are terminated by null bytes")),
 		{OPTION_LOWLEVEL_CALLBACK, 0, "stdin", &read_from_stdin, NULL,
 			N_("read list of paths to be updated from standard input"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
 			(parse_opt_cb *) stdin_callback},
-		{OPTION_LOWLEVEL_CALLBACK, 0, "index-info", &line_termination, NULL,
+		{OPTION_LOWLEVEL_CALLBACK, 0, "index-info", &nul_term_line, NULL,
 			N_("add entries from standard input to the index"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
 			(parse_opt_cb *) stdin_cacheinfo_callback},
@@ -1057,6 +1060,8 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		}
 	}
 	argc = parse_options_end(&ctx);
+
+	getline_fn = nul_term_line ? strbuf_getline_nul : strbuf_getline_lf;
 	if (preferred_index_format) {
 		if (preferred_index_format < INDEX_FORMAT_LB ||
 		    INDEX_FORMAT_UB < preferred_index_format)
@@ -1073,9 +1078,9 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;
 
 		setup_work_tree();
-		while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
+		while (getline_fn(&buf, stdin) != EOF) {
 			char *p;
-			if (line_termination && buf.buf[0] == '"') {
+			if (!nul_term_line && buf.buf[0] == '"') {
 				strbuf_reset(&nbuf);
 				if (unquote_c_style(&nbuf, buf.buf, NULL))
 					die("line is badly quoted");