Re: Re: Re: Homebrew and Git

From: Stefan Beller <sbeller@google.com>
Date: Sep 22, 2016, 15:57 UTC
Message-ID: <CAGZ79kYUcyCrjPfqWtyWE-kaqbQZPG1qosc3qJrDfHixivyFew@mail.gmail.com>
In-Reply-To: <trinity-7a55c197-21af-4808-9919-6fc26bdcece2-1474536212197@3capp-gmx-bs75>

On Thu, Sep 22, 2016 at 2:23 AM, Jonas Thiel <jonas.lierschied@gmx.de> wrote:

> Sorry for my late reply. Thanks for your support -- I really appreciate that.
>
> @Jeff: Unfortunately, I do not know how to implement the patch you provided. Can you explain how to do that?

I think this should do:

    git clone https://github.com/git/git
    cd git
    # get the email
    wget http://public-inbox.org/git/20160921084841.phq7cfbagi5k7ku4@sigill.intra.peff.net/raw
    # apply patch:
    git am raw
    make
    make install

Show 68 quoted lines

>
> Thanks and best regards,
> Jonas
>
>> Gesendet: Mittwoch, 21. September 2016 um 10:48 Uhr
>> Von: "Jeff King" <peff@peff.net>
>> An: "John Keeping" <john@keeping.me.uk>
>> Cc: "Heiko Voigt" <hvoigt@hvoigt.net>, "Jonas Thiel" <jonas.lierschied@gmx.de>, git@vger.kernel.org
>> Betreff: Re: Re: Homebrew and Git
>>
>> On Tue, Sep 20, 2016 at 08:15:55PM +0100, John Keeping wrote:
>>
>> > > BTW, here is the callstack inlined from the crashreport:
>> > >
>> > > bsystem_platform.dylib            0x00007fff840db41c _platform_strchr$VARIANT$Haswell + 28
>> > > 1   git                                   0x000000010ba1d3f4 ident_default_email + 801
>> > > 2   git                                   0x000000010ba1d68f fmt_ident + 66
>> > > 3   git                                   0x000000010ba4b495 files_log_ref_write + 175
>> > > 4   git                                   0x000000010ba4b0a6 commit_ref_update + 106
>> > > 5   git                                   0x000000010ba4c3a8 ref_transaction_commit + 468
>> > > 6   git                                   0x000000010b994dd8 s_update_ref + 271
>> > > 7   git                                   0x000000010b994556 fetch_refs + 1969
>> > > 8   git                                   0x000000010b9935f2 fetch_one + 1913
>> > > 9   git                                   0x000000010b992bc4 cmd_fetch + 549
>> > > 10  git                                   0x000000010b9666c4 handle_builtin + 478
>> > > 11  git                                   0x000000010b96602f main + 376
>> > > 12  libdyld.dylib                         0x00007fff834ef5ad start + 1
>> > >
>> > > Maybe someone else has an idea what might be causing this...
>> >
>> > The only strchr I can see that could be called here is in
>> > canonical_name(), where it's called with addrinfo::ai_canonname.
>>
>> There's one in add_domainname(), too, but it can never be NULL (we could
>> walk off the end of the buffer, but only if gethostname() lies to us
>> about its result code, which seems unlikely). So I agree it's probably
>> the call in canonical_name().
>>
>> > Searching for OS X and ai_canonname, leads me straight back to this
>> > list, although 7 years ago!  I think ident.c needs a fix similar to
>> > commit 3e8a00a (daemon.c: fix segfault on OS X, 2009-04-27); from the
>> > commit message there:
>> >
>> >     On OS X (and maybe other unices), getaddrinfo(3) returns NULL
>> >     in the ai_canonname field if it's called with an IP address for
>> >     the hostname.
>>
>> Interesting. We are already prepared for failure from getaddrinfo()
>> here, so probably:
>>
>> diff --git a/ident.c b/ident.c
>> index e20a772..d17b5bd 100644
>> --- a/ident.c
>> +++ b/ident.c
>> @@ -101,7 +101,7 @@ static int canonical_name(const char *host, struct strbuf *out)
>>       memset (&hints, '\0', sizeof (hints));
>>       hints.ai_flags = AI_CANONNAME;
>>       if (!getaddrinfo(host, NULL, &hints, &ai)) {
>> -             if (ai && strchr(ai->ai_canonname, '.')) {
>> +             if (ai && ai->ai_canonname && strchr(ai->ai_canonname, '.')) {
>>                       strbuf_addstr(out, ai->ai_canonname);
>>                       status = 0;
>>               }
>>
>> would be sufficient. Jonas, can you see if that patch helps?
>>
>> -Peff
>>