Cherry-pick and Reflog¶

Overview¶

Production is on release/2.1 but the fix landed on main — cherry-pick copies that commit without merging entire branches. Accidentally ran git reset --hard — reflog remembers where HEAD was yesterday. These tools are essential for hotfix backports and disaster recovery.

This is Tutorial 14 in Module 5: Recovery & Debugging of the REBASH Academy Git series.

Prerequisites¶

• Undoing Changes — Reset, Revert, and Stash
• Rebasing and Interactive Rebase

Learning Objectives¶

By the end of this tutorial, you will be able to:

• Cherry-pick commits onto another branch
• Resolve cherry-pick conflicts and continue/abort
• Cherry-pick ranges and multiple commits
• Use reflog to find lost commits and branches
• Recover from reset, rebase, and deleted branch mistakes
• Backport hotfixes to release branches
• Understand reflog expiration and limitations

Cherry-pick and Reflog Diagram¶

flowchart LR
    MAIN["main: commit FIX"]
    REL["release/2.1"]
    MAIN -->|git cherry-pick FIX| REL

    HEAD[HEAD moves]
    REFLOG["(reflog<br/>90 day journal")]
    HEAD --> REFLOG
    REFLOG -->|git reset --hard SHA| RECOVER[Recovered state]

Theory¶

git cherry-pick¶

Applies the patch of a specific commit onto current branch — new commit, new SHA, same diff (usually):

git switch release/2.1
git cherry-pick abc1234

Use cases:

• Hotfix backport — fix on main → cherry-pick to release branch
• Selective feature — one commit from large feature branch
• Recover single commit from abandoned branch

Cherry-pick vs Merge¶

Cherry-picked commits appear twice in history (different SHAs) — document in release notes.

Conflict Resolution¶

Same as merge/rebase:

# fix conflicts
git add resolved-file
git cherry-pick --continue
git cherry-pick --abort
git cherry-pick --skip

Cherry-pick Range¶

git cherry-pick A..B      # commits after A through B (exclusive A)
git cherry-pick A^..B     # include A

Order matters — applies oldest first.

Cherry-pick Merge Commits¶

Requires -m to specify mainline parent — rarely needed; prefer cherry-picking individual commits from feature branch.

No-commit Cherry-pick¶

git cherry-pick -n abc1234   # apply without committing

Useful to combine multiple picks into one commit.

Reflog — Git's Safety Journal¶

Reflog records when HEAD and branch tips moved:

git reflog
git reflog show main

Format: SHA HEAD@{n}: action: description

Entries include commits reachable even after reset — local only, not pushed to remote.

Recovery Scenarios¶

Lost after hard reset:

git reflog
git reset --hard HEAD@{3}

Deleted branch:

git reflog | grep "checkout: moving from feature"
git switch -c feature-recovered SHA

Failed rebase:

git reflog
git reset --hard HEAD@{1}   # before rebase started

Reflog Expiration¶

Default: 90 days for reachable commits, 30 days for unreachable. Configurable via gc.reflogExpire. Don't rely on reflog as permanent backup.

git cherry — Already Applied?¶

Check if commit exists on branch:

git cherry main feature-branch

+ means not on main; - means equivalent patch present.

Hands-on Lab¶

Step 1 – Build main and release branches¶

Command:

mkdir -p /tmp/git-cherry-lab && cd /tmp/git-cherry-lab
git init -b main
echo "v2.0" > VERSION && git add . && git commit -m "release: v2.0 baseline"
git switch -c release/2.0
git switch main
echo "fix: critical patch" >> patch.log
git add patch.log && git commit -m "fix: critical security patch"
FIX_SHA=$(git rev-parse HEAD)
git log --oneline --all

Step 2 – Cherry-pick fix to release¶

Command:

git switch release/2.0
git cherry-pick "$FIX_SHA"
git log --oneline --graph --all
cat patch.log

Step 3 – Simulate disaster and recover¶

Command:

git switch main
git branch -D release/2.0
git reflog | head -10
RECOVER=$(git rev-parse "$FIX_SHA")
git switch -c release/2.0-recovered HEAD~1
git cherry-pick "$RECOVER"
git log --oneline -3

Step 4 – Reflog after hard reset¶

Command:

git switch main
TIP=$(git rev-parse HEAD)
git reset --hard HEAD~2
git log --oneline -2
git reset --hard "$TIP"
git log --oneline -3

Step 5 – Cherry-pick conflict¶

Command:

git switch -c conflict-demo HEAD~2
echo "different" > patch.log && git add . && git commit -m "conflict setup"
git switch main
git cherry-pick HEAD~1 2>/dev/null || git cherry-pick $(git rev-parse conflict-demo) || true
# Manual resolution if conflict:
git status
git cherry-pick --abort 2>/dev/null || true

Step 6 – Clean up¶

Command:

cd /tmp && rm -rf git-cherry-lab

Commands & Code¶

Hotfix backport script¶

#!/usr/bin/env bash
# backport.sh — cherry-pick commit to release branch
set -euo pipefail
COMMIT="${1:?Usage: backport.sh COMMIT_SHA release/x.y}"
RELEASE="${2:?release branch required}"
git fetch origin
git switch "$RELEASE"
git pull --ff-only origin "$RELEASE"
git cherry-pick -x "$COMMIT"
git push origin "$RELEASE"
echo "Backported $COMMIT to $RELEASE"

Common Mistakes¶

Best Practices¶

Troubleshooting¶

Summary¶

• Cherry-pick applies specific commit(s) to current branch — ideal for hotfix backports
• Use -x for audit trail; resolve conflicts like merge/rebase
• Reflog records local HEAD movements — primary recovery tool after reset/rebase
• Reflog is local and time-limited — not a substitute for remote backup
• git cherry verifies whether commits already exist on target branch

Interview Questions¶

1. What does git cherry-pick do?
2. When would you cherry-pick instead of merge?
3. How do you recover a commit after git reset --hard?
4. What is reflog, and where is it stored?
5. How long does reflog retain entries?
6. What does cherry-pick -x add to commit messages?
7. How do you cherry-pick a range of commits?
8. Why doesn't reflog help recover deleted remote branches?
9. What is the difference between cherry-pick and revert?
10. How do you abort a failed cherry-pick?

Related Tutorials¶

• Undoing Changes — Reset, Revert, and Stash (previous)
• Git Bisect and Debugging History (next)
• Rebasing and Interactive Rebase
• Merging and Merge Conflicts
• Git – Category Overview

References¶

• Pro Git Book – Rebasing – Cherry-picking
• git cherry-pick documentation
• git reflog documentation
• Atlassian – git reflog
• REBASH Academy – Git Overview