From: Nikolaus Schuetz <nikolauspschuetz@gmail.com>

git-check-ref-format(1) documents that a refname cannot contain a
space, tilde, caret, colon, question-mark, asterisk, open-bracket or
backslash, nor the sequence "..", and cannot be the single character
"@".  Of these, only "?", "\" and ".." were tested embedded in an
otherwise-valid refname; "*" was checked only as a lone character or
with --refspec-pattern.

Test all of them in that embedded form with a single loop, and check
that "@" alone is rejected even with --allow-onelevel -- where "@" is
otherwise a valid refname component, as "refs/@" confirms.

Signed-off-by: Nikolaus Schuetz <nikolauspschuetz@gmail.com>

Submitted-As: https://lore.kernel.org/git/pull.2203.v2.git.1787264417682.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.2203.git.1786653837190.gitgitgadget@gmail.com