Subject: Re: [PATCH v7 1/9] connect: document why we sometimes call get_port after get_host_and_port

From: Torsten Bögershausen <[email-masked]>
Date: Thu, 26 May 2016 07:35:23 +0200

On 05/26/2016 01:34 AM, Mike Hommey wrote:
> On Tue, May 24, 2016 at 06:44:26AM +0200, Torsten Bögershausen wrote:
>> On 05/23/2016 11:30 PM, Junio C Hamano wrote:
>>> Torsten Bögershausen <[email-masked]> writes:
>>>
>>>>>>>     			get_host_and_port(&ssh_host, &port);
>>>>>>>     +			/* get_host_and_port may not return a port
>>>>>>> even when
>>>>>>> +			 * there is one: In the [host:port]:path case,
>>>>>>> +			 * get_host_and_port is called with "[host:port]" and
>>>>>>> +			 * returns "host:port" and NULL.
>>>>>>> +			 * In that specific case, we still need to split the
>>>>>>> +			 * port. */
>>>>>> Is it worth to mention that this case is "still supported legacy" ?
>>>>> If it's worth mentioning anywhere, it seems to me it would start with
>>>>> urls.txt?
>>>>>
>>>>> Mike
>>>>>
>>>> I don't know.
>>>> urls.txt is for Git users, and connect.c is for Git developers.
>>>> urls.txt does not mention that Git follows any RFC when parsing the
>>>> URLS', it doesn't claim to be 100% compliant.
>>>> Even if it makes sense to do so, as many user simply expect Git to accept
>>>> RFC compliant URL's, and it makes the development easier, if there is
>>>> an already
>>>> written specification, that describes all the details.
>>>> The parser is not 100% RFC compliant, one example:
>>>> - old-style usgage like "git clone [host:222]:~/path/to/repo are supported
>>> Is it an option to fix get_host_and_port() so that it returns what
>>> the caller expects even when it is given "[host:port]"?  When the
>>> caller passes other forms like "host:port", it expects to get "host"
>>> and "port" parsed out into two variables.  Why can't the caller
>>> expect to see the same happen when feeding "[host:port]" to the
>>> function?
>>>
>> This is somewhat out of my head:
>> git clone   git://[example.com:123]:/test        #illegal, malformated URL
>> git clone   [example.com:123]:/test               #scp-like URL, legacy
>> git clone   ssh://[example.com:123]:/test       #illegal, but supported as
>> legacy, because
>> git clone  ssh://[user@::1]/test                       # was the only way to
>> specify a user name at a literal IPv6 address
>>
>> May be we should have some  more test cases for malformated git:// URLs?
>
> None of these malformed urls are rejected with or without my series
> applied:
>
> Without:
> $ git fetch-pack --diag-url git://[example.com:123]:/test
> Diag: url=git://[example.com:123]:/test
> Diag: protocol=git
> Diag: hostandport=[example.com:123]:
> Diag: path=/test
> $ git fetch-pack --diag-url
> ssh://[example.com:123]:/test
> Diag: url=ssh://[example.com:123]:/test
> Diag: protocol=ssh
> Diag: userandhost=example.com
> Diag: port=123
> Diag: path=/test
>
> With:
> $ git fetch-pack --diag-url git://[example.com:123]:/test
> Diag: url=git://[example.com:123]:/test
> Diag: protocol=git
> Diag: user=NULL
> Diag: host=example.com
> Diag: port=123
> Diag: path=/test
> $ git fetch-pack --diag-url ssh://[example.com:123]:/test
> Diag: url=ssh://[example.com:123]:/test
> Diag: protocol=ssh
> Diag: user=NULL
> Diag: host=example.com
> Diag: port=123
> Diag: path=/test
>
> Note in the first case, hostandport is "[example.com:123]:", and that
> is treated as host=example.com:123 and port=NULL further down, so my
> series is changing something here, but arguably, it makes it less worse.
> (note that both with and without my series,
> "git://[example.com:123]:42/path" is treated the same, so only a corner
> case changed)
>
> Can we go forward with the current series (modulo the comment style
> thing Eric noted, and maybe adding a note about the parser handling urls
> as per urls.txt), and not bloat scope it? If anything, the state of the
> code after the series should make further parser changes easier.
>
> Cheers,
>
> Mike
>

Thanks for digging.

How about something like this:

/*
  * get_host_and_port may not return a port in the [host:port]:path case.
  * To support this undocumented legacy we still need to split the port.
*/