Re: RFD: fast-import is picky with author names (and maybe it should - but how much so?)

> A Large Angry SCM <gitzilla@gmail.com> writes:
>
>> On 11/11/2012 07:41 AM, Felipe Contreras wrote:
>>> On Sat, Nov 10, 2012 at 8:25 PM, A Large Angry SCM<gitzilla@gmail.com>  wrote:
>>>> On 11/10/2012 01:43 PM, Felipe Contreras wrote:
>>>
>>>>> So, the options are:
>>>>>
>>>>> a) Leave the name conversion to the export tools, and when they miss
>>>>> some weird corner case, like 'Author<email', let the user face the
>>>>> consequences, perhaps after an hour of the process.
>>>>>
>>>>> We know there are sources of data that don't have git-formatted author
>>>>> names, so we know every tool out there must do this checking.
>>>>>
>>>>> In addition to that, let the export tool decide what to do when one of
>>>>> these bad names appear, which in many cases probably means do nothing,
>>>>> so the user would not even see that such a bad name was there, which
>>>>> might not be what they want.
>>>>>
>>>>> b) Do the name conversion in fast-import itself, perhaps optionally,
>>>>> so if a tool missed some weird corner case, the user does not have to
>>>>> face the consequences.
>>>>>
>>>>> The tool writers don't have to worry about this, so we would not have
>>>>> tools out there doing a half-assed job of this.
>>>>>
>>>>> And what happens when such bad names end up being consistent: warning,
>>>>> a scaffold mapping of bad names, etc.
>>>>>
>>>>>
>>>>> One is bad for the users, and the tools writers, only disadvantages,
>>>>> the other is good for the users and the tools writers, only
>>>>> advantages.
>>>>>
>>>>
>>>> c) Do the name conversion, and whatever other cleanup and manipulations
>>>> you're interesting in, in a filter between the exporter and git-fast-import.
>>>
>>> Such a filter would probably be quite complicated, and would decrease
>>> performance.
>>>
>>
>> Really?
>>
>> The fast import stream protocol is pretty simple. All the filter
>> really needs to do is pass through everything that isn't a 'commit'
>> command. And for the 'commit' command, it only needs to do something
>> with the 'author' and 'committer' lines; passing through everything
>> else.
>>
>> I agree that an additional filter _may_ decrease performance somewhat
>> if you are already CPU constrained. But I suspect that the effect
>> would be negligible compared to the all of the SHA-1 calculations.
>
> More importantly, which do users prefer: quickly produce an
> incorrect result, or spend some more time to get it right?

> Because the exporting tool has a lot more intimate knowledge about
> how the names are represented in the history of the original SCM,
> canonicalization of the names, if done at that point, would likely
> to give us more useful results, than a canonicalization done at the
> beginning of the importer, which lacks SCM specific details.  So in
> that sense, (a) is more preferrable than (b).

> On the other hand, we would want consistency across the converted
> results no matter what SCM the history was originally in.  E.g. a
> name without email that came from CVS or SVN would consistently want
> to become "name <noname@noname>" or "name <name>" or whatever, and
> letting exporting tools responsible for the canonicalization will
> lead them to create their own garbage.  In that sense, (b) can be
> better than (a).