# Canonical way to filter list of commits to those pointed to by branches (preserving order)?

1 messages from 2025-06-10 to 2025-06-10. Participants: D. Ben Knoble.
Thread: https://gitlist.dev/t/63619

## D. Ben Knoble, 2025-06-10 21:29

Subject: Canonical way to filter list of commits to those pointed to by branches (preserving order)?
Message-ID: <20250610212954.51868-1-ben.knoble+github@gmail.com>
URL: https://gitlist.dev/e/20250610212954.51868-1-ben.knoble%2Bgithub%40gmail.com

```
Perusing a Git Rev News article [1], I thought there must be a better way to
turn the commits between 2 revisions into a list of branch names—better, that
is, than parsing git-log output.

I wound up with 3 options, but I wonder if any are canonical or if I'm missing
the "standard" approach? My current best attempt leaves me concerned via the
documentation.

1. Use join:

    join <(git rev-list "$upstream..$base" | sort) \
         <(git for-each-ref --format="%(objectname) %(refname:strip=2)" refs/heads | sort)

    Requires Bash or Zsh due to process substitution, and the |sort pipe loses
    topological order. But elegant, from a certain point of view, perhaps.

2. Use git-name-rev, but post-process output (because name-rev gives results
that aren't refs):

    git rev-list "$upstream..$base" | xargs git name-rev --refs='refs/heads/*' |
      while read -r sha ref; do
        if git check-ref-format --branch "$ref" >/dev/null 2>&1; then
          printf '%s %s\n' "$sha" "$ref"
        fi
      done

    Not my favorite, but seems to work

3. Use git-name-rev after filtering with --simplify-by-decoration

    git rev-list --simplify-by-decoration "$upstream..$base" | xargs git name-rev

    Clearly the most elegant, but only if I can rely on --simplify-by-decoration
    not outputting commits not pointed directly to by a branch. But the docs say
    "Note that extra commits can be shown to give a meaningful history." Hm. (Of
    course, all the git-name-rev solutions are broken in the presence of tags,
    too, though for my use case I will just ignore that for now…)

[1]: Pushing a whole stack of branches with a single Git command <https://andrewlock.net/pushing-a-whole-stack-of-branches-with-a-single-git-command/>

--
D. Ben Knoble

```