Re: [PATCH 2/4] submodule--helper clone: simplify path check

From: Stefan Beller <sbeller@google.com>
Date: Mar 31, 2016, 17:17 UTC
Message-ID: <CAGZ79kYbX5dggD7cs1PRHpkUS2gRTp1fAmt3mg1n1Og3ZB3fRw@mail.gmail.com>
In-Reply-To: <CAPig+cTz3fTyXFM4oPNO3Tv6dP0hN152jf9_JZOrsAZad1+O6Q@mail.gmail.com>

On Thu, Mar 31, 2016 at 12:31 AM, Eric Sunshine <sunshine@sunshineco.com> wrote:

Show 15 quoted lines

> On Wed, Mar 30, 2016 at 8:17 PM, Stefan Beller <sbeller@google.com> wrote:
>> The calling shell code makes sure that `path` is non null and non empty.
>> (side note: it cannot be null as just three lines before it is passed
>> to safe_create_leading_directories_const which would crash as you feed
>> it null).
>
> I'm confused by this. So, you're saying that it's okay (and desirable)
> for git-submodule--helper to segfault when the user does this:
>
>     % git submodule--helper clone
>     Segmentation fault: 11
>
> rather than, say, printing a useful error message, such as:
>
>     submodule--helper: missing or empty --path

I think I was rather saying,
* that you see the segfault behavior not at all when channeling
   the command through the proper frontend command
* that it already crashes (we access *path before this check,
  so this check is pointless)

> While one can argue that this is an
> internal command only invoked in a controlled fashion, it's not hard
> to imagine someone running it manually to understand its behavior or
> to debug some problem.

(additionally:) And later we may want to reuse this code when replacing the frontend command to be written in C completely.

>    if (!path || !*path)
>        die(_("submodule--helper: unspecified or empty --path"));

That sounds good to me. I'll pick it up.