Re: [RFC PATCH v2 06/12] submodule--helper: add a '--stage' option to the 'config' sub command

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 2, 2018, 18:57 UTC
Message-ID: <xmqqd0v01trp.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180802134634.10300-7-ao2@ao2.it>

Antonio Ospite <ao2@ao2.it> writes:

> Add a --stage option to the 'submodule--helper config' command so that
> the .gitmodules file can be staged without referring to it explicitly by
> its file path.

Sorry, but I have no clue what the above is trying to say.

The original 's--h config <name> [<value>]' is quite understandable. It is like "git config <name> [<value>]", i.e. either get the current value for the name, or set a new value to the name.

What does this 's--h config --stage' that does not take any option do? "git add .gitmodules"? Something else? In what meaning is the word "stage" used? Is it used as a verb "to stage"?

In a series that lets us use the data in the .gitmodules file without materializing the file in the working tree, I would have expected that you would want an option to specify which .gitmodules among (1) the one in the working tree (i.e. the only option we currently have), (2) the one in the index, and (3) the one in the HEAD, and when I saw the title, I would have expected that

	git submodule--helper config --stage name

may be a way to read from the .gitmodules in the index to find the value for name (however, we we follow the option naming convention in gitcli.txt, it should be called --cached, I would think).

> In practice the config will still be written to .gitmodules, there are
> no plans to change the file path, but having this level of indirection
> makes it possible to perform additional checks before staging the file.

Again, a claim without explanation or justification.

If you are planning to something like

 - prepare trial contents in .gitmodules.new file
 - do whatever "additional checks" on .gitmodules.new
 - add the contents to it to the index as a new .gitmodules blob

Then you do not need such an option. "submodule--helper" is purely a helper for scripts, and not for human consumption, so scripts can just hash-object the blob contents out and update-index --cacheinfo to register the blob at any location of choice.

But as I said, this step is way under-explained, so my guess above may not match what you really wanted to do.