fix: auto-stash creates empty stash objects from untracked noise (#19)

[stackbilt-admin]

Summary

• Fixes fix: auto-stash creates empty stash objects from untracked noise files, no cleanup #19 — the auto-stash preflight was creating empty stash objects from untracked-only dirty state, with no cleanup, causing stashes to accumulate indefinitely across autonomous runs.
• Only stashes on real tracked changes now, detected via git diff --quiet and git diff --cached --quiet.
• Dropped --include-untracked from the stash push — untracked files are left alone (the worktree cleanup path handles them separately).
• Added an empty-stash guard: post-push, verify the stash tree differs from its parent, drop immediately if not.
• Applied symmetrically to taskrunner.sh and plugin/taskrunner.sh.

Root cause

# Old:
if [[ -n "$(git status --porcelain 2>/dev/null)" ]]; then
  git stash push -m "cc-taskrunner:${task_id:0:8}" --include-untracked 2>/dev/null && stashed=true
fi

status --porcelain includes untracked files. Running in a repo that has charter CLI writing telemetry to .charter/telemetry/events.ndjson (or any equivalent untracked noise) triggers a stash on every task run. Combined with --include-untracked, the stash object is created with a tree that ends up matching HEAD — empty diff, but still a real stash entry.

Without a cleanup path, stashes pile up forever.

Real-world evidence

From a production fork after routine operation:

$ git stash list
stash@{0}: On main: cc-taskrunner: auto-stash before task 16c2374a-...
stash@{1}: On main: cc-taskrunner: auto-stash before task 3a6c2503-...
stash@{2}: On main: cc-taskrunner: auto-stash before task 45149a3f-...
... (10 entries total)

$ git stash show stash@{0} --include-untracked --stat
 web/.charter/telemetry/events.ndjson | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

$ git stash show stash@{1} --include-untracked --stat
 (empty)
$ # ...same for stash@{2} through stash@{9}

The fix

# New:
local has_tracked_dirty=false
if ! git diff --quiet 2>/dev/null; then has_tracked_dirty=true; fi
if ! git diff --cached --quiet 2>/dev/null; then has_tracked_dirty=true; fi

if $has_tracked_dirty; then
  if git stash push -m "cc-taskrunner:${task_id:0:8}" 2>/dev/null; then
    if ! git diff stash@{0}^1 stash@{0} --quiet 2>/dev/null; then
      stashed=true
      log "│  Stashed uncommitted tracked changes"
    else
      git stash drop stash@{0} 2>/dev/null || true
      log "│  Stash was empty after push — dropped"
    fi
  fi
fi

Test plan

Verified with a 5-scenario synthetic test in a throwaway repo:

• Clean tree → skipped
• Untracked noise only → skipped (previously: empty stash)
• Tracked file modified → stashed, real content
• Stash pop → recovers content correctly
• Staged changes only → stashed, real content

All scenarios pass. Bash syntax verified via bash -n on both files.

Related

• Fork downstream has already landed this fix and a separate .gitignore cleanup for **/.charter/telemetry/ (which is what exposed the bug — .charter/telemetry/ at the root .gitignore doesn't match nested paths in monorepos).
• Follow-up feat: blast radius preflight gate via charter blast #20 proposes a blast-radius preflight gate that builds on top of this cleaned-up preflight pipeline.

🤖 Generated with Claude Code