Re: [PATCH] multi-pack-index: fix potential segfault without sub-command
flat view
From: Jeff King <hidden>
Date: 2021-07-21 08:13:57
On Mon, Jul 19, 2021 at 01:18:49PM -0400, Taylor Blau wrote:
Since cd57bc41bb (builtin/multi-pack-index.c: display usage on unrecognized command, 2021-03-30) we have used a "usage" label to avoid having two separate callers of usage_with_options (one when no arguments are given, and another for unrecognized sub-commands). But the first caller has been broken since cd57bc41bb, since it will happily jump to usage without arguments, and then pass argv[0] to the "unrecognized subcommand" error. Many compilers will save us from a segfault here, but the end result is ugly, since it mentions an unrecognized subcommand when we didn't even pass one, and (on GCC) includes "(null)" in its output. Move the "usage" label down past the error about unrecognized subcommands so that it is only triggered when it should be. While we're at it, bulk up our test coverage in this area, too.
Good find. The code change seems obviously correct.
quoted hunk ↗ jump to hunk
+test_expect_success 'usage shown without sub-command' ' + test_expect_code 129 git multi-pack-index 2>err && + ! test_i18ngrep "unrecognized subcommand" err +'
I think we're avoiding test_i18ngrep in new code these days. -Peff