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

From: Jeff King <peff@peff.net>
Date: Mar 21, 2018, 07:50 UTC
Message-ID: <20180321075041.GA24701@sigill.intra.peff.net>
In-Reply-To: <CAHnyXxTf16ukf8CFSfzjQjTEjf5yJXFqK5TnS9KiXZEeAD7dgg@mail.gmail.com>

On Wed, Mar 21, 2018 at 03:36:09AM -0400, Dakota Hawkins wrote:

Show 7 quoted lines

> > I think that ignoring all of /ignore-most/ is much more efficient, since
> > we don't have to enumerate the paths inside it at all (which is why the
> > current behavior works as it does).
> 
> That's definitely true, but I wonder what the impact would be for most
> cases (even for most cases with large repos and larges sets of ignore
> files).

Probably not that much CPU, but it used to be quite annoying to fault in the dcache for an infrequently used hierarchy. These days I generally have an SSD and lots of memory for disk caching, so I don't know if it would still be.

On systems where readdir/stat are slower than Linux it might be noticeable for a big hierarchy.

Show 5 quoted lines

> At any rate, would it at least be a good idea to make the "trailing
> slash halts recursion, won't consider nested .gitignore files"
> explicit in the `.gitignore` doc? Unless I'm missing it, I don't think
> that behavior is called out (or at least not called out concisely/in
> one place). It looks like this is all there is:

Yeah, it's definitely come up multiple times over the years. I don't know what all is in gitignore(5), but if it's not mentioned it probably should be.

Show 10 quoted lines

>     "If the pattern ends with a slash, it is removed for the purpose
> of the following description, but it would only find a match with a
> directory. In other words, foo/ will match a directory foo and paths
> underneath it, but will not match a regular file or a symbolic link
> foo (this is consistent with the way how pathspec works in general in
> Git)."
> 
> Also, I'm not sure what the "following description" is in "it is
> removed for the purpose of the following description". Is that trying
> to imply "excluded from the rest of the doc"?

I think it means "for the rest of the description of how the patterns work". I.e., "foo/" matches as "foo" when the rest of the matching rules are applied. I agree it's a bit awkward. Patches welcome. :)

-Peff