Re: [PATCH] rev-parse: Check argc before using argv[i+1]

From: David Sharp <dhsharp@google.com>
Date: Jan 28, 2014, 21:20 UTC
Message-ID: <CAJL_ekuMJByFDVLMCYD4fo9EQy3LKdohsw25WfHqJv9M=3S9Kw@mail.gmail.com>
In-Reply-To: <xmqqtxcnly39.fsf@gitster.dls.corp.google.com>

On Tue, Jan 28, 2014 at 11:12 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 15 quoted lines

> David Sharp <dhsharp@google.com> writes:
>
>> @@ -738,9 +740,11 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
>>                               continue;
>>                       }
>>                       if (!strcmp(arg, "--resolve-git-dir")) {
>> -                             const char *gitdir = resolve_gitdir(argv[i+1]);
>> +                             if (++i >= argc)
>> +                                     die("--resolve-git-dir requires an argument");
>> +                             const char *gitdir = resolve_gitdir(argv[i]);
>>                               if (!gitdir)
>> -                                     die("not a gitdir '%s'", argv[i+1]);
>> +                                     die("not a gitdir '%s'", argv[i]);
>
> This adds decl-after-statement.

Sorry, I wasn't aware that git is trying to conform to C90. (It's not compiled with -std=c90, -ansi or -Wdeclaration-after-statement.)

> As referencing argv[argc] is not a
> crime (you will grab a NULL), how about doing it this way to see if
> the value is a NULL, instead of comparing the index and argc?

I'm not convinced this is any better, but alright. I did something slightly different based on that, though.

v2 patch incoming...

Show 11 quoted lines

>
>         const char *gitdir;
>         if (!argv[++i])
>                 die("--resolve-git-dir requires an argument");
>         gitdir = resolve_gitdir(argv[i]);
>         if (!gitdir)
>                 die("not a gitdir '%s'", argv[i]);
>
> Same comment may apply to other hunks.
>
> Thanks.