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

From: Johannes Sixt <j6t@kdbg.org>
Date: Nov 19, 2021, 20:05 UTC
Message-ID: <190a1fea-124d-2e85-38ea-9dab87f3e377@kdbg.org>
In-Reply-To: <72fffbff-16f7-fa17-b212-67aae9e1b034@gmail.com>

Am 19.11.21 um 15:51 schrieb Derrick Stolee:

Show 14 quoted lines

> What is unclear to me is what exactly "match a directory" means.
> If we ignore a directory, then we ignore everything inside it (until
> another pattern says we should care about it), but the converse
> should also hold: if we have a pattern like "!data/**/", then that
> should mean "include everything inside data/<A>/ where <A> is any
> directory name".
> 
> My inability to form a mental model where the existing behavior
> matches the documented specification is an indicator that this was
> changed erroneously. A revert patch is included at the end of this
> message.
> 
> If anyone could help clarify my understanding here, then maybe
> there is room for improving the documentation.

You form a wrong mental model when you start with the grand picture of a working tree. That is, when you say

- here I have theeeeeese many files and directories,
- and I want to ignore some: foo/**/,
- but I don't want to ignore others: !bar/**/.

This forms the wrong mental model because that is not how Git sees the working tree: it never has a grand picture of all of its contents.

Git only ever sees the contents of one directory. When Git determines that a sub-directory is ignored, then that one's contents are never inspected, and there is no opportunity to un-ignore some of the sub-directory's contents.

-- Hannes