Re: [PATCH] rev-parse: Detect missing opt-spec

SZEDER Gábor [off-list ref] writes:

On Fri, Sep 02, 2022 at 07:06:21AM +0200, Øystein Walle wrote:

quoted

If a line in parseopts's input starts with one of the flag characters it
is erroneously parsed as a opt-spec where the short name of the option
is the flag character itself and the long name is after the end of the
string. This makes Git want to allocate SIZE_MAX bytes of memory at this
line:

    o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);

Since s and sb.buf are equal the second argument is -2 (except unsigned)
and xmemdupz allocates len + 1 bytes, ie. -1 meaning SIZE_MAX.

I suspect (but didn't actually check) that this bug was added in
2d893dff4c (rev-parse --parseopt: allow [*=?!] in argument hints,
2015-07-14).

Good thing to add to the proposed log message.  Thanks.

Also, Øystein "Detect" -> "detect" on the title (you can see the
convention in the output from "git shortlog --no-merges").

quoted

 		if (!s)
 			s = help;
 
+		if (s == sb.buf)
+			die(_("Missing opt-spec before option flags"));
+

OK.

quoted

+test_expect_success 'test --parseopt invalid opt-spec' '
+	test_write_lines x -- "=, x" >spec &&
+	echo "fatal: Missing opt-spec before option flags" >expect &&
+	test_must_fail git rev-parse --parseopt -- >out <spec >actual 2>&1 &&

When checking an error message please don't look for it on standard
output; i.e. the redirection at the end should be '2>actual', or
perheps even better '2>err'.

Again, very good point.

Thanks.