git-clone --single-branch clones objects outside of branch

Hi,

I'm reporting some git-clone behavior regarding --single-branch that I found unexpected after reading the docs. I'm using git 2.25.0.

The git-clone docs for --single-branch say:

(from: https://git-scm.com/docs/git-clone#Documentation/git-clone.txt---no-single-branch )

However, when I attempted this with a local repo, I found that objects located only in branches other than the branch I specified are also cloned. Also, this is true even if the remote repo has only loose objects (i.e. no pack files). So it doesn't appear to be doing this only to avoid creating new files.

In contrast, git-fetch behaves as expected (including locally). git-fetch appears to fetch only objects in the given branch, when a branch is specified.

Below are some commands to assist with reproducing this situation (but you will need to update the path in the `git-remote add` invocation below). At the least, it seems like the docs should clarify the behavior. (The Python commands were for when I was doing some experiments with pack files.)

mkdir repo1 cd repo1 git init python -c "print('a\n' + 10 * 'x\n')" > a.txt git add a.txt git commit -m "add a" # Get object id to check existence with `git cat-file -t` below. git hash-object a.txt

git checkout -b dev python -c "print('b\n' + 10 * 'x\n')" > b.txt git add b.txt git commit -m "add b" # Get object id to check existence with `git cat-file -t` below. git hash-object b.txt

git checkout master

cd .. mkdir repo2 cd repo2 git init git remote add other file:///<path-to-repo1> git fetch other master

cd .. git clone --branch master --single-branch repo1 repo3

Thanks, --Chris