Re: [PATCH nd/attr-match-optim-more 2/2] attr: more matching optimizations from .gitignore

[Johannes Sixt <j.sixt@viscovery.net>]

Am 10/9/2012 7:08, schrieb Junio C Hamano:
> Imagine if we allowed only one attribute per line, instead of
> multiple attributes on one line.
>     
>  - If you want to unset the attribute, you would write "path -attr".
> 
>  - If you want to reset the attribute to unspecified, you would
>    write "path !attr".
> 
> Both are used in conjunction with some other (typically more
> generic) pattern that sets, sets to a value, and/or unsets the
> attribute, to countermand its effect.
> 
> If you were to allow "!path attr", what does it mean?  It obviously
> is not about setting the attr to true or to a string value, but is
> it countermanding an earlier set and telling us to unset the attr,
> or make the attr unspecified?

If I have at the toplevel:

  *.txt  whitespace=tabwidth=4

and in a subdirectory

  *.txt  whitespace=tabwidth=8
  !README.txt

it could be interpreted as "do not apply *.txt to REAME.txt in this
subdirectory". That is, it does not countermand some _particular_
attribute setting, but says "use the attributes collected elsewhere".

-- Hannes