Re: .gittattributes handling has deficiencies

From: david@lang.hm <david@lang.hm>
Date: Oct 21, 2007, 23:49 UTC
Message-ID: <Pine.LNX.4.64.0710211645210.12998@asgard.lang.hm>
In-Reply-To: <C7F59DFB-D4E4-4F75-88F7-F1A90C7D41E8@zib.de>

On Sun, 21 Oct 2007, Steffen Prohaska wrote:

Show 34 quoted lines

> On Oct 21, 2007, at 7:57 PM, david@lang.hm wrote:
>
>> On Sun, 21 Oct 2007, Steffen Prohaska wrote:
>> 
>>> On Oct 21, 2007, at 7:09 PM, david@lang.hm wrote:
>>> 
>>>> On Sun, 21 Oct 2007, Steffen Prohaska wrote:
>>>>> On Oct 21, 2007, at 11:19 AM, david@lang.hm wrote:
>>>>>>> But this is really hard to solve. We would need to compare
>>>>>>> attributes before and after for _all_ files that have attributes
>>>>>>> in one of the two commits and check if they changed. If so, we
>>>>>>> need to do a fresh checkout according to the new attributes.
>>>>>> if you know that you will get the new .gitattributes if it changes, 
>>>>>> setup a post-checkout hook to checkout everything if it has changed. 
>>>>>> it's far from ideal, but it should be a good, safe, first 
>>>>>> approximation.
>>>>> That's not good enough. I'll stop using .gitattributes. I
>>>>> need to teach >40 devs how to use git on Windows. I only use
>>>>> features that work flawlessly. .gitattributes doesn't. It bit
>>>>> me twice now.
>>>> why would checking everything out if .gitattributes has changed not work? 
>>>> I can see why _not_ doing so would cause problems, and I freely 
>>>> acknowledge that this approach imposes a performance hit by checking 
>>>> everything out twice, but I don't see how it would not be reliable.
>>> 
>>> What do you mean by "checking out everything"?
>>> Which command do you propose?
>> 
>> something like git checkout -f
>
> I suspected this. I see two problems:
>
> 1) it's too dangerous: I throws away _all_ changes, not only
> changes that are related to gitattributes.

this is true, the question of if this is 'too dangerous' depends on what workflow you teach as safe. if you teach that checking out a new version will loose any modifications you have made (which is useually the sane thing to do by default anyway) then this is just more of the same

> 2) it doesn't work reliably. git checkout -f will only update
> files that git detects as changed. But you could have files that
> should have crlf in the working copy but actually have only lf.
> Those would not be updated.

ok, you could do rm -r * before doing the checkout -f (or there's probably a option to git to tell it not to preserve changes to the working area, I am not a git guru.

> I'll not recommend this. Not using .gitattributes is the only
> sane solution.

it may be the best thing to do for you and your users, that's not the same thing as saying that it's the only sane solution.

David Lang