Re: [PATCHv3 1/4] notes: don't leak memory in git_config_get_notes_strategy

[Junio C Hamano <gitster@pobox.com>]

Eric Sunshine <sunshine@sunshineco.com> writes:

> On Thu, Mar 31, 2016 at 2:04 PM, Stefan Beller <sbeller@google.com> wrote:
>> `value` is just a temporary scratchpad, so we need to make sure it doesn't
>> leak. It is xstrdup'd in `git_config_get_string_const` and
>> `parse_notes_merge_strategy` just compares the string against predefined
>> values, so no need to keep it around longer. Instead of using
>> `git_config_get_string_const`, use `git_config_get_value`, which doesn't
>> return a copy.
>>
>> Signed-off-by: Stefan Beller <sbeller@google.com>
>> ---
>> diff --git a/builtin/notes.c b/builtin/notes.c
>> @@ -746,7 +746,7 @@ static int git_config_get_notes_strategy(const char *key,
>>  {
>>         const char *value;
>>
>> -       if (git_config_get_string_const(key, &value))
>> +       if (git_config_get_value(key, &value))
>
> Hmm, doesn't this introduce a rather severe regression? Unless I'm
> misreading the code (possible), with the original, if 'key' was
> boolean (lacked a value in the config file), then it would complain:
>
>     Missing value for 'floop.blork'
>
> but, with this change, it will dereference NULL and crash.
>
> (My understanding was that Peff's suggestion to use
> git_config_get_value() implied a bit of work beyond the simple textual
> substitution of 'git_config_get_value' for
> 'git_config_get_string_const'.)

Yup, thanks for spelling it out.