Christian Couder <christian.couder@xxxxxxxxx> 于2023年8月2日周三 18:25写道：
>
> On Wed, Aug 2, 2023 at 9:50 AM ZheNing Hu <adlternative@xxxxxxxxx> wrote:
> >
> > In my case, I often need to use "git rev-parse --verify" to verify
> > if a revision exists in the repository, and this usually works:
> >
> > git rev-parse --verify HEAD
> > afa5ff0f56bc60d1c9abe839726e7fb2105a9ca3
> >
> > git rev-parse --verify afa5ff0f56bc60d1c9abe839726e7fb2105a9ca3
> > afa5ff0f56bc60d1c9abe839726e7fb2105a9ca3
> >
> > git rev-parse --verify aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
> > fatal: Needed a single revision
> >
> > However, when I started checking for a non-existent OID that happened
> > to be exactly 40 characters long, something unexpected happened.
> > "git rev-parse --verify" did not produce any error messages.
> > I consider this to be a BUG.
> >
> > git rev-parse --verify aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
> > aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
>
> The doc says:
>
> "
> --verify
> Verify that exactly one parameter is provided, and that it
> can be turned into a raw 20-byte SHA-1 that can be used to access the
> object database. If so, emit it to the standard output;
> otherwise, error out.
>
So why doesn't "git rev-list --verify" check if 20-byte SHA-1 can
"access the object database"?
> If you want to make sure that the output actually names an
> object in your object database and/or can be used as a specific type
> of object you require, you can add the ^{type} peeling
> operator to the parameter. For example, git rev-parse
> "$VAR^{commit}" will make sure $VAR names an existing object that is a
> commit-ish (i.e. a commit, or an annotated tag that points
> at a commit). To make sure that $VAR names an existing
> object of any type, git rev-parse "$VAR^{object}" can be used.
> "
>
> So "--verify <argument>" only checks that the <argument> provided to
> it can be turned into a raw 20-byte SHA-1 (or perhaps a raw 32-byte
> SHA256 in case the repo is using SHA256). "^{object}" should be added
> at the end of the <argument> if you want to verify that the raw
> 20-byte SHA-1 (or the raw 32-byte SHA256) also corresponds to an
> actual object in the repo.
>
> $ git rev-parse --verify aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa^{object}
> fatal: Needed a single revision
>
> Hope this helps.
Thank you, your method is effective for me.
