git-clang-format removes unstaged files

[adorostkar]

Hi all,
While running git clang-format I have come to a scenario where the script doesn't work as expected.

How to reproduce

1. Have staged changes in file A which require reformatting
2. Have staged changes in file B which don’t require reformatting
3. Have unstaged changes in file B which are actual changes (let’s say new function)
4. Run git clang-format --staged

The effect:

• Unstaged changes in A which is the format change.
• New changes in file B are deleted. <- this is the wrong behavior

Additional info

2. The version of the clang-format and the script is 16.0.6
3. I am running this on MacOs

If the changes that need formatting are staged in B and anything else is not staged in B then the git-clang-format refuses to format and prints a message saying that there are unstaged changes.

[owenca]

/cherry-pick 743659b