biultin/rev-parse: fix memory leaks in `--parseopt` mode

We have a bunch of memory leaks in git-rev-parse(1)'s `--parseopt` mode.
Refactor the code to use `struct strvec`s to make it easier for us to
track the lifecycle of those leaking variables and then free them.

While at it, remove the unneeded static lifetime for some of the
variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 30 insertions, 23 deletions

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 1e2919fd81..ab8a8f3b0e 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -423,12 +423,12 @@ static char *findspace(const char *s)
 
 static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 {
-	static int keep_dashdash = 0, stop_at_non_option = 0;
-	static char const * const parseopt_usage[] = {
+	int keep_dashdash = 0, stop_at_non_option = 0;
+	char const * const parseopt_usage[] = {
 		N_("git rev-parse --parseopt [<options>] -- [<args>...]"),
 		NULL
 	};
-	static struct option parseopt_opts[] = {
+	struct option parseopt_opts[] = {
 		OPT_BOOL(0, "keep-dashdash", &keep_dashdash,
 					N_("keep the `--` passed as an arg")),
 		OPT_BOOL(0, "stop-at-non-option", &stop_at_non_option,
@@ -438,12 +438,11 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 					N_("output in stuck long form")),
 		OPT_END(),
 	};
-	static const char * const flag_chars = "*=?!";
-
 	struct strbuf sb = STRBUF_INIT, parsed = STRBUF_INIT;
-	const char **usage = NULL;
+	struct strvec longnames = STRVEC_INIT;
+	struct strvec usage = STRVEC_INIT;
 	struct option *opts = NULL;
-	int onb = 0, osz = 0, unb = 0, usz = 0;
+	size_t opts_nr = 0, opts_alloc = 0;
 
 	strbuf_addstr(&parsed, "set --");
 	argc = parse_options(argc, argv, prefix, parseopt_opts, parseopt_usage,
@@ -453,16 +452,16 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 
 	/* get the usage up to the first line with a -- on it */
 	for (;;) {
+		strbuf_reset(&sb);
 		if (strbuf_getline(&sb, stdin) == EOF)
 			die(_("premature end of input"));
-		ALLOC_GROW(usage, unb + 1, usz);
 		if (!strcmp("--", sb.buf)) {
-			if (unb < 1)
+			if (!usage.nr)
 				die(_("no usage string given before the `--' separator"));
-			usage[unb] = NULL;
 			break;
 		}
-		usage[unb++] = strbuf_detach(&sb, NULL);
+
+		strvec_push(&usage, sb.buf);
 	}
 
 	/* parse: (<short>|<short>,<long>|<long>)[*=?!]*<arghint>? SP+ <help> */
@@ -474,10 +473,10 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 		if (!sb.len)
 			continue;
 
-		ALLOC_GROW(opts, onb + 1, osz);
-		memset(opts + onb, 0, sizeof(opts[onb]));
+		ALLOC_GROW(opts, opts_nr + 1, opts_alloc);
+		memset(opts + opts_nr, 0, sizeof(*opts));
 
-		o = &opts[onb++];
+		o = &opts[opts_nr++];
 		help = findspace(sb.buf);
 		if (!help || sb.buf == help) {
 			o->type = OPTION_GROUP;
@@ -494,20 +493,22 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 		o->callback = &parseopt_dump;
 
 		/* name(s) */
-		s = strpbrk(sb.buf, flag_chars);
+		s = strpbrk(sb.buf, "*=?!");
 		if (!s)
 			s = help;
 
 		if (s == sb.buf)
 			die(_("missing opt-spec before option flags"));
 
-		if (s - sb.buf == 1) /* short option only */
+		if (s - sb.buf == 1) { /* short option only */
 			o->short_name = *sb.buf;
-		else if (sb.buf[1] != ',') /* long option only */
-			o->long_name = xmemdupz(sb.buf, s - sb.buf);
-		else {
+		} else if (sb.buf[1] != ',') { /* long option only */
+			o->long_name = strvec_pushf(&longnames, "%.*s",
+						    (int)(s - sb.buf), sb.buf);
+		} else {
 			o->short_name = *sb.buf;
-			o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
+			o->long_name = strvec_pushf(&longnames, "%.*s",
+						    (int)(s - sb.buf - 2), sb.buf + 2);
 		}
 
 		/* flags */
@@ -537,9 +538,9 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 	strbuf_release(&sb);
 
 	/* put an OPT_END() */
-	ALLOC_GROW(opts, onb + 1, osz);
-	memset(opts + onb, 0, sizeof(opts[onb]));
-	argc = parse_options(argc, argv, prefix, opts, usage,
+	ALLOC_GROW(opts, opts_nr + 1, opts_alloc);
+	memset(opts + opts_nr, 0, sizeof(*opts));
+	argc = parse_options(argc, argv, prefix, opts, usage.v,
 			(keep_dashdash ? PARSE_OPT_KEEP_DASHDASH : 0) |
 			(stop_at_non_option ? PARSE_OPT_STOP_AT_NON_OPTION : 0) |
 			PARSE_OPT_SHELL_EVAL);
@@ -547,7 +548,13 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 	strbuf_addstr(&parsed, " --");
 	sq_quote_argv(&parsed, argv);
 	puts(parsed.buf);
+
 	strbuf_release(&parsed);
+	strbuf_release(&sb);
+	strvec_clear(&longnames);
+	strvec_clear(&usage);
+	free((char *) opts->help);
+	free(opts);
 	return 0;
 }