From: Jonathan Nieder <jrnieder@gmail.com>
Date: Mon, 25 Sep 2017 20:04:48 GMT
Subject: Re: [PATCH] t7406: submodule.<name>.update command must not be run from .gitmodules
Message-ID: <20170925200448.GY27425@aiede.mtv.corp.google.com>
In-Reply-To: <20170925195533.15172-1-sbeller@google.com>

Stefan Beller wrote:

> submodule.<name>.update can be assigned an arbitrary command via setting
> it to "!command". When this command is found in the regular config, Git
> ought to just run that command instead of other update mechanisms.
> 
> However if that command is just found in the .gitmodules file, it is
> potentially untrusted, which is why we do not run it.  Add a test
> confirming the behavior.
> 
> Suggested-by: Jonathan Nieder <jrnieder@gmail.com>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  t/t7406-submodule-update.sh | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
> index 034914a14f..780af4e6f5 100755
> --- a/t/t7406-submodule-update.sh
> +++ b/t/t7406-submodule-update.sh
> @@ -406,6 +406,16 @@ test_expect_success 'submodule update - command in .git/config' '
>  	)
>  '
>  
> +test_expect_success 'submodule update - command in .gitmodules is ignored' '
> +	test_when_finished "git -C super reset --hard HEAD^" &&
> +
> +	git -C super config -f .gitmodules submodule.submodule.update "!false || echo >bad" &&

What does the '!false || echo >bad' do?

Ideally we want this test to be super robust: e.g. if it runs the
command but from a different directory, we still want the test to fail,
and if it runs the command but using exec instead of a shell, we still
want the test to fail.

Maybe write_script would help with this.  E.g. would something like

	test_when_finished ... &&
	write_script must_not_run.sh <<-EOF &&
	>$TEST_DIRECTORY/bad
	EOF

	git -C super config -f .gitmodules submodule.submodule.update \
		"!$TEST_DIRECTORY/must_not_run.sh" &&
	...

work?

Thanks,
Jonathan