Re: [PATCH 01/15] read-cache: fix memleak

> Stefan Beller <sbeller@google.com> writes:
>
>> `ce` is allocated in make_cache_entry and should be freed if it is not
>> used any more. refresh_cache_entry as a wrapper around refresh_cache_ent
>> will either return `ce` or a new updated cache entry which is allocated
>> to new memory. In that case we need to free `ce` ourselfs.
>>
>> Signed-off-by: Stefan Beller <sbeller@google.com>
>> ---
>>  read-cache.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/read-cache.c b/read-cache.c
>> index 8d71860..f72ea9f 100644
>> --- a/read-cache.c
>> +++ b/read-cache.c
>> @@ -747,6 +747,8 @@ struct cache_entry *make_cache_entry(unsigned int mode,
>>               free(ce);
>>               return NULL;
>>       } else {
>> +             if (ret != ce)
>> +                     free(ce);
>>               return ret;
>>       }
>>  }
>
> Good, I vaguely recall that we did something similar in another
> codepath that forgot the fact that refresh_cache_entry() may make
> the incoming ce unnecessary.
>
> As the rule is "if ret is different from ce, then ce must be freed"
> in this codepath, I wonder if this is easier to read:
>
>         ret = refresh_cache_entry(ce, ...);
>         if (ret != ce)
>                 free(ce);
>         return ret;
>