Re: git 2.34.0: Behavior of `**` in gitignore is different from previous versions.

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 21, 2021, 00:46 UTC
Message-ID: <xmqq5ysmnxnx.fsf@gitster.g>
In-Reply-To: <CAPx1GveHusi8n8n03hUwBu6B3=_j0ZY6FWXWKDs8mLGwHEN-Qg@mail.gmail.com>

Chris Torek <chris.torek@gmail.com> writes:

Show 23 quoted lines

> ...  So the standard
> explanation -- at least, the one I use -- is this:
>
>  * Git opens and reads the working tree directory.  For each file
>    or directory that is actually present here, Git checks it
>    against the ignore rules.  Some rules match only directories
>    and others match both directories and files.  Some rules say
>    "do ignore" and some say "do not ignore".
>
>  * The *last* applicable rule wins.
>
>  * If this is a file and the file is ignored, it's ignored.
>    Unless, that is, it's in the index already, because then it's
>    tracked and can't be ignored.
>
>  * If this is a directory and the directory is ignored, it's
>    not even opened and read.  It's not in the index because
>    directories are never in the index (at least nominally).
>    If it is opened and read, the entire set of rules here
>    apply recursively.
>
> This works, but skips over files that are in the index and are in
> a directory that won't be read.  So I add one last rule, which is

All of the above is sensible. If you deal with a path that is in the index upfront, you can simplify the later rules somewhat, I would think. I.e. add a first rule before everything else that says:

 * A file in the index is not ignored.  Everything below is about a
   path not in the index.

Then your third rule can lose "Unless...", and you do not have to add one last rule outside the bulleted list, either.

;-)