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Re: .gitattributes override behavior (possible bug, or documentation bug)

From
DHDakota Hawkins <dakota@dakotahawkins.com>
Date
Mar 20, 2018, 03:17 UTC
Message-ID
<CAHnyXxR+03P8vG02dSuDCnRG0vsbOEWWsNBsKVsedgpkPNu=fQ@mail.gmail.com>
In-Reply-To
<CAHnyXxRcwq40W4tKm=Kscrsnb77yh7=eGDE=r5AZq073MPX9AQ@mail.gmail.com>
Sorry to tack on to my previous email, but I just thought of this:

If something like "-diff=lfs" won't do what I (and git-lfs) thought it would, do you think it would be prudent/reasonable to suggest git-lfs add a "no-lfs" filter for exactly this case? That way I could have explicit exclusions without any "diff=foo" shenanigans.

Thanks again,
- Dakota

On Mon, Mar 19, 2018 at 11:10 PM, Dakota Hawkins <dakota@dakotahawkins.com> wrote:

Show 109 quoted lines
> Thanks for the quick reply!
>
> On Mon, Mar 19, 2018 at 10:34 PM, Jeff King <peff@peff.net> wrote:
>> On Mon, Mar 19, 2018 at 09:49:28PM -0400, Dakota Hawkins wrote:
>>
>>> Summary: Trying to apply attributes to file extensions everywhere
>>> except in one directory.
>>>
>>> .gitattributes:
>>>
>>>     *.[Pp][Nn][Gg] filter=lfs diff=lfs merge=lfs -text
>>>     /.readme-docs/ -filter=lfs -diff=lfs -merge=lfs
>>>
>>> Make some data:
>>>
>>>     echo "asldkjfa;sldkjf;alsdjf" > ./.readme-docs/test.png
>>>     git add -A
>>
>> As you noted below, that second line does not match your path, because
>> attributes on a directory aren't applied recursively. And it has nothing
>> to do with overriding. If you remove the png line entirely, you can see
>> that we still do not match it. You need to use "*" to match the paths.
>
> Ah, yes, I see that. Inconsistent with .gitignore (more below), right?
>
>> You may also find that "-diff=lfs" does not do quite what you want.
>> There is no way to say "cancel any previous attribute", which I think is
>> what you're trying for here. You can only override it with a new value.
>> So:
>>
>>   /.readme-docs/* -diff
>>
>> says "do not diff this". And:
>>
>>   /.readme-docs/* diff
>>
>> says "diff this as text, even if it looks binary".
>>
>> The best you can probably do is:
>>
>>   /.readme-docs/* diff=foo
>>
>> Since you have no diff.foo.* config, that will behave in the default way
>> (including respecting the usual "is it binary" checks). So a bit hacky,
>> but I think it would work as "ignore prior diff".
>>
>> And I think filter and merge drivers should work the same.
>
> That's interesting... in this case I was taking my advice on how this
> should work from the git-lfs folks. I have promised to share what I
> find here with them, so that will help at least :)
>
> I think that makes sense to me -- there would be no good way to tell
> it what the default should have been without explicitly telling it
> what to use instead.
>
>>> Is this me misunderstanding something in the documentation? I would
>>> expect "./.readme-docs/" to match "./.readme-docs/test.png" and
>>> override the earlier "*.[Pp][Nn][Gg]" attributes.
>>>
>>> I have found the following overrides to work in lieu of the directory match:
>>>
>>>     /.readme-docs/* -filter=lfs -diff=lfs -merge=lfs
>>>     /.readme-docs/**/* -filter=lfs -diff=lfs -merge=lfs
>>>
>>> ...but I don't see a justification in the documentation for this
>>> working and the original directory filter not working.
>>
>> I could not find anything useful in gitattributes(5). There's some old
>> discussion here:
>>
>>   https://public-inbox.org/git/slrnkldd3g.1l4.jan@majutsushi.net/
>
> If I follow that correctly: There's some initial speculation that it
> would be OK to apply the attributes recursively, which is then shot
> down because it wasn't designed to be recursive (though I don't see a
> different, technical reason for that), followed by finding a (this
> same?) solution/workaround for the original problem. Is that about
> right?
>
>> which makes it clear that attributes aren't recursive, but it's probably
>> worth calling out in the documentation. In fact, I think the current
>> documentation is a bit misleading in that it says "patterns are matched
>> as in .gitignore", which is clearly not the case here.
>
> I was indeed going off of the suggestion to consult the .gitignore
> pattern matching documentation.
>
>> I think just "/.readme-docs/**" should be sufficient for your case. You
>> could also probably write "*" inside ".readme-docs/.gitattributes",
>> which may be simpler (you don't need "**" there because patterns without
>> a slash are just matched directly against the basename).
>
> Wouldn't that make the "*" inside ".readme-docs/.gitattributes",
> technically recursive when "*" matches a directory? It's always seemed
> to me that both were necessary to explicitly match things in a
> directory and its subdirectories (example, IIRC: "git ls-files --
> .gitattributes" vs "git ls-files -- .gitattributes
> **/.gitattributes"). Maybe that example is peculiar in that its a
> dotfile and can't have a wildcard before the dot?
>
> I guess my takeaway is that it would be _good_ if the gitattributes
> documentation contained the caveat about not matching directories
> recursively, but _great_ if gitattributes and gitignore (and whatever
> else there is) were consistent.
>
> At any rate, thanks for the great, quick help!
>
> -Dakota
Previous: Dakota HawkinsNext: Jeff King
Message 4 of 28 in “.gitattributes override behavior (possible bug, or documentation bug)”
  1. Dakota HawkinsMar 20, 2018
  2. Jeff KingMar 20, 2018
  3. Dakota HawkinsMar 20, 2018
  4. Dakota HawkinsMar 20, 2018
  5. Jeff KingMar 20, 2018
  6. Jeff KingMar 20, 2018
  7. doc/gitattributes: mention non-recursive behaviorJeff King, Mar 20, 2018
  8. Dakota HawkinsMar 20, 2018
  9. Duy NguyenMar 20, 2018
  10. Jeff KingMar 21, 2018
  11. Duy NguyenMar 21, 2018
  12. Jeff KingMar 23, 2018
  13. Dakota HawkinsMar 20, 2018
  14. Jeff KingMar 20, 2018
  15. Dakota HawkinsMar 20, 2018
  16. Duy NguyenMar 20, 2018
  17. Dakota HawkinsMar 21, 2018
  18. Jeff KingMar 21, 2018
  19. Dakota HawkinsMar 21, 2018
  20. Dakota HawkinsMar 21, 2018
  21. Jeff KingMar 21, 2018
  22. Dakota HawkinsMar 21, 2018
  23. Jeff KingMar 21, 2018
  24. Junio C HamanoMar 21, 2018
  25. Duy NguyenMar 21, 2018
  26. Junio C HamanoMar 20, 2018
  27. Dakota HawkinsMar 20, 2018
  28. Jeff KingMar 20, 2018

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