Re: [PATCH] Workaround for ai_canonname sometimes coming back as null

From: Alex Riesen <raa.lkml@gmail.com>
Date: Apr 29, 2009, 22:01 UTC
Message-ID: <81b0412b0904291501w501eecd4y18927018d57bdbdc@mail.gmail.com>
In-Reply-To: <6B7EA51D-8412-4E6A-BA7B-156FD5B755E8@gmail.com>

2009/4/29 Augie Fackler <durin42@gmail.com>:

Show 23 quoted lines

> On Apr 29, 2009, at 4:55 PM, Alex Riesen wrote:
>> 2009/4/29 Augie Fackler <durin42@gmail.com>:
>>>
>>> @@ -459,7 +459,10 @@ static void parse_extra_args(char *extra_args, int
>>> buflen)
>>>                               inet_ntop(AF_INET, &sin_addr->sin_addr,
>>>                                         addrbuf, sizeof(addrbuf));
>>>                               free(canon_hostname);
>>> -                               canon_hostname =
>>> xstrdup(ai->ai_canonname);
>>> +                               if (ai->ai_canonname)
>>> +                                       canon_hostname =
>>> xstrdup(ai->ai_canonname);
>>> +                               else
>>> +                                       canon_hostname = "unknown";
>>
>> This last line will crash some lines down, when canon_hostname is free'd:
>>
>
> Odd, because I'm running with that exact code and not seeing the problem.
> Should I resubmit an updated patch that xstrdup's unknown into
> canon_hostname?
>

I think you can just let canon_hostname be NULL (i.e. don't strdup it, if ai_canonname is NULL). NULL values of canon_hostname seem to be handled just fine: see path_ok and strbuf_expand_dict_cb (strbuf.c)