Hi,
I noticed the following (possible bug?) when I tried to create zstd tar
archive (.tar.zst) with `git archive`.
First, I created the plain tar archive with `git archive`, then extract
and rearchive to zstd tar achive:
```
(on the repo)
$ git archive -o /tmp/something.tar --prefix=something/ HEAD
(outside the repo, on /tmp)
$ tar xvf something.tar
$ tar --zstd -c -v -f something.tar.zst something/
```
I checked that the archive was indeed zstd tar archive:
```
$ file something.tar.zst
something.tar.zst: Zstandard compressed data (v0.8+), Dictionary ID: None
```
Now I created the same archive with `git archive` directly:
```
(on the repo)
$ git archive -o /tmp/something1.tar.zst --prefix=something/ HEAD
```
But that archive info (with `file`) was something different:
```
(outside the repo, on /tmp)
$ file something1.tar.zst
something1.tar.zst: POSIX tar archive
```
I expected that `something1.tar.zst` was proper zstd tar archive, and
not plain archive like above.
--
An old man doll... just what I always wanted! - Clara
