Re: [PATCH 2/4] builtin/rev-parse: learn --null-oid

From: Taylor Blau <me@ttaylorr.com>
Date: Sep 20, 2020, 15:35 UTC
Message-ID: <20200920153537.GA2726066@nand.local>
In-Reply-To: <20200918212609.GC67496@camp.crustytoothpaste.net>

On Fri, Sep 18, 2020 at 09:26:09PM +0000, brian m. carlson wrote:

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> What I typically do when I write shell scripts, and which may obviate
> the need for this patch is turn this:
>
>   [ "$oid" = 0000000000000000000000000000000000000000 ]
>
> into this:
>
>   echo "$oid" | grep -qsE '^0+$'
>
> This is slightly less efficient, but it's also backwards compatible
> with older Git version assuming you have a POSIX grep.

Yeah, I mostly just have no idea how common this is in the wild. If many scripts care about the null OID, then a '--null-oid' makes sense to me. But if it's only a few, then it does not.

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> If you still want this option, then that's fine, but please make
> --null-oid take the same arguments as --show-object-format (and default
> to the same value).  Git will soon learn about writing SHA-1 while
> storing in SHA-256, and it makes everyone's life better if we can plan
> for the future by making it understand these options now.

Agreed.

Show 7 quoted lines

> I'm not sure we need an empty tree and empty blob object, because it's
> pretty easy to write these:
>
>   git hash-object -t tree /dev/null
>   git hash-object -t blob /dev/null
>
> That's what I've done in some of the transition code at least.

I could go either way. This for some reason seems more common to me, so I wouldn't mind making it easier for callers, but I don't care so much because what you already wrote is easy enough as-is.

> --
> brian m. carlson: Houston, Texas, US

Thanks, Taylor