GPT老师的指导：恢复误删的git stash

You can often recover a dropped stash because Git keeps the underlying commit and blob objects for a while (until garbage collection). Act quickly and avoid commands that run aggressive GC.

What to try first (quick recovery)

1. Find the stash commit via reflog:

• git reflog show stash
  • If it lists the dropped entry, note its commit hash (e.g., 168db1867e3f... from your message).

If you see the hash
2) Recreate the stash reference:

• Option A: Recreate as a branch to inspect:
  • git branch recover-stash 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
  • git checkout recover-stash
  • Your stashed changes will be in the commit’s tree (for “stash save/ push” with index/worktree, see notes below).
• Option B: Restore as a new stash ref:
  • git update-ref refs/stash 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
  • git stash list
  • You should now see it again (likely as stash@{0}), and can git stash apply.

If stash isn’t in reflog
3) Search all reflogs and unreachable commits:

• git reflog --all | grep 168db1867e3f
  • If not known, just list everything and look for “stash” or “WIP”:
  • git reflog --all | grep -i stash
  • git log -g --grep=stash --all
• Use fsck to find dangling commits:
  • git fsck --lost-found --no-reflogs
  • Look for “dangling commit ” around the time you stashed.
• Explore the commit objects by time:
  • git log --walk-reflogs --date=iso --all
  • Or show recent unreachable objects:
  • git fsck --no-reflogs --lost-found | grep commit | head -n 50

Once you find the stash commit hash
4) Understand stash structure to extract content:

• A typical stash object is a merge commit with up to three parents:
  • Parent 1: the commit you were on when stashing (base).
  • Parent 2: the index (staged) state.
  • Parent 3: the worktree (unstaged) state (only present if there were unstaged changes).
• To inspect:
  • git show --summary --no-patch 168db1867e3f
  • git show 168db1867e3f^1 # base
  • git show 168db1867e3f^2 # index tree
  • git show 168db1867e3f^3 # worktree tree (if exists)

5. Recover files/changes from the stash commit:

• To restore both index and worktree like “apply”:
  • git stash apply 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
• If apply isn’t available (ref not under refs/stash), use checkout/restore of the trees:
  • To get working copy back to the stashed worktree:
    • git checkout 168db1867e3fe74ef7cbfc26d7dae39bebebcddf^3 -- .
      (If ^3 doesn’t exist, use ^2 for staged-only stash.)
  • To stage the index part:
    • git checkout 168db1867e3fe74ef7cbfc26d7dae39bebebcddf^2 -- .
• Or create a branch at the worktree parent and merge:
  • git switch -c stash-recovered 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
  • git merge -s ours --no-commit 168db1867e3fe74ef7cbfc26d7dae39bebebcddf^1
  • git read-tree -mu 168db1867e3fe74ef7cbfc26d7dae39bebebcddf^3

If you only have the hash from the drop message

• You do: 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
• Try restoring the stash ref directly:
  • git update-ref refs/stash 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
  • Then: git stash list; git stash apply

Edge cases and tips

• If git stash apply errors with “Not a stash reference”: ensure the ref is refs/stash or refs/stash@{n}. update-ref fixes that.
• If no ^3 parent exists, your stash only had staged changes; use ^2.
• If fsck shows dangling blobs but not the stash commit, you can still recover specific files:
  • git show > path/to/file
  • But prefer recovering the stash commit if possible.
• Avoid garbage collection until you recover:
  • Do not run git gc --prune=now
  • If autoGC runs, it usually keeps recent objects, but time matters.
• Make a safety clone before experimenting:
  • git clone --no-hardlinks . ../repo-recovery
  • Work in the recovery clone to avoid accidental prune.

Quick one-liner if your hash is valid right now

• git update-ref refs/stash 168db1867e3fe74ef7cbfc26d7dae39bebebcddf && git stash apply

If this fails, paste the output of:

• git rev-parse 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
• git cat-file -t 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
• git show --summary 168db1867e3fe74ef7cbfc26d7dae39bebebcddf
  And I’ll guide you through the next step.