git reset と revert と restore の違い - コミットを安全に取り消す選び方

ワーキングツリー      インデックス           HEAD とブランチ
(実際のファイル)      (次のコミットの内容)    (最新コミットへの参照)
 
    app.txt   ──git add──>   app.txt   ──git commit──>   main -> a508fb0

$ git log --oneline
a508fb0 commit C
57d1928 commit B
30138d3 commit A

$ git reset --soft HEAD~1
$ git status --short
M  app.txt
$ git log --oneline
57d1928 commit B
30138d3 commit A

$ git reset --soft HEAD~2
$ git status --short
M  app.txt
$ git commit -q -m "squashed B and C"
$ git log --oneline
2b72cdf squashed B and C
30138d3 commit A

$ git reset HEAD~1
Unstaged changes after reset:
M	app.txt
$ git status --short
 M app.txt

$ git reset --hard HEAD~1
HEAD is now at 57d1928 commit B
$ cat app.txt
A
B

$ git status --short
 M app.txt
?? untracked.txt
$ git reset --hard
HEAD is now at a508fb0 commit C
$ git status --short
?? untracked.txt

$ git clean -n
Would remove u.txt
$ git clean -f
Removing u.txt

# notes.txt を編集中に、notes.txt に関係ない「commit D」を取り消す
$ git status --short
 M notes.txt
$ git reset --keep HEAD~1
$ git status --short
 M notes.txt
$ cat notes.txt
keepme
localedit

$ git status --short
 M app.txt
$ git reset --keep HEAD~1
error: Entry 'app.txt' not uptodate. Cannot merge.
fatal: Could not reset index file to revision 'HEAD~1'.

$ git merge --no-edit topic
Auto-merging app.txt
CONFLICT (content): Merge conflict in app.txt
Automatic merge failed; fix conflicts and then commit the result.
$ git status --short
UU app.txt
 M notes.txt
$ git reset --merge
$ git status --short
 M notes.txt

$ git reset app.txt
Unstaged changes after reset:
M	app.txt
$ git reset --hard app.txt
fatal: Cannot do hard reset with paths.

$ git revert --no-edit HEAD
[main 32aac5e] Revert "commit D"
 Date: Mon Nov 9 10:00:00 2026 +0900
 1 file changed, 1 deletion(-)
$ git log --oneline -3
32aac5e Revert "commit D"
f7c25bb commit D
a508fb0 commit C
$ git log -1 --format=%B
Revert "commit D"
 
This reverts commit f7c25bbb80404e645d0ac42e272ad8af82061325.

$ git revert --no-edit HEAD
error: Your local changes to the following files would be overwritten by merge:
	app.txt
Please commit your changes or stash them before you merge.
Aborting
fatal: revert failed

$ git revert --no-edit HEAD~2..HEAD
[main 32aac5e] Revert "commit D"
 ...
[main 71bee41] Revert "commit C"
 ...
$ git log --oneline -6
71bee41 Revert "commit C"
32aac5e Revert "commit D"
f7c25bb commit D
a508fb0 commit C
57d1928 commit B
30138d3 commit A

$ git revert -n HEAD~2..HEAD
$ git status --short
M  app.txt
$ git commit -q -m "Revert commits C and D"
$ git log --oneline -3
e8fbd28 Revert commits C and D
f7c25bb commit D
a508fb0 commit C

$ git revert --no-edit HEAD~1
Auto-merging app.txt
CONFLICT (content): Merge conflict in app.txt
error: could not revert a508fb0... commit C
$ git revert --abort

$ git log --oneline --graph -5
*   1dd3f18 Merge branch 'feature'
|\
| * 4cbcb48 feature: add f1
* | 5414455 main: add m1
|/
* 22e1378 add base
* f7c25bb commit D
$ git log -1 --format='parents: %p'
parents: 5414455 4cbcb48
 
$ git revert --no-edit HEAD
error: commit 1dd3f1801891b7ed24a520d8b106079a1ed69a66 is a merge but no -m option was given.
fatal: revert failed

$ git revert --no-edit -m 1 HEAD
[main 9f7ca86] Revert "Merge branch 'feature'"
 Date: Mon Nov 9 10:00:00 2026 +0900
 1 file changed, 1 deletion(-)
 delete mode 100644 feature.txt

$ git merge --no-edit feature
Already up to date.

# feature に fix.txt を足すコミットを作ってから
$ git merge --no-edit feature
Merge made by the 'ort' strategy.
 fix.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 fix.txt
$ ls
app.txt
base.txt
fix.txt
main.txt

$ git revert --no-edit 9f7ca86
[main 269fbe0] Reapply "Merge branch 'feature'"
 Date: Mon Nov 9 10:00:00 2026 +0900
 1 file changed, 1 insertion(+)
 create mode 100644 feature.txt
$ ls
app.txt
base.txt
feature.txt
fix.txt
main.txt

git revert <revertコミット>   # 消した変更を戻す
git merge feature             # 修正分を取り込む

$ git merge --no-edit feature
Already up to date.
$ git merge --no-ff --no-edit feature-v2
Merge made by the 'ort' strategy.
 feature.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 feature.txt

$ git status
On branch main
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
	modified:   app.txt
 
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   app.txt

# ワーキングツリーの変更を破棄する（add していない変更が失われる）
$ echo wip >> app.txt
$ git status --short
 M app.txt
$ git restore app.txt
$ git status --short
 
# add を取り消す（ファイルの変更は残る）
$ git add app.txt
$ git status --short
M  app.txt
$ git restore --staged app.txt
$ git status --short
 M app.txt
 
# add した変更ごと破棄する
$ git restore --staged --worktree app.txt

$ git restore u.txt
error: pathspec 'u.txt' did not match any file(s) known to git
$ git status --short
A  n.txt
$ git restore --staged n.txt
$ git status --short
?? n.txt

$ git restore --source=HEAD~2 app.txt
$ git status --short
 M app.txt
$ cat app.txt
A

$ git restore --source=HEAD~1 --staged --worktree app.txt
$ git status --short
M  app.txt

$ git reset --hard HEAD~1
HEAD is now at 269fbe0 Reapply "Merge branch 'feature'"
$ git push origin main
To ../origin.git
 ! [rejected]        main -> main (non-fast-forward)
error: failed to push some refs to '../origin.git'

$ git push --force-with-lease origin main
To ../origin.git
 + 56b0d7a...269fbe0 main -> main (forced update)
 
# 他の人がリモートに push した後だと拒否される
$ git push --force-with-lease origin main
To ../origin.git
 ! [rejected]        main -> main (stale info)
error: failed to push some refs to '../origin.git'

$ git fetch -q origin
$ git push -n --force-with-lease origin main
To ../origin.git
 + b90a6c0...08b0ea2 main -> main (forced update)

$ git push -n --force-with-lease --force-if-includes origin main
To ../origin.git
 ! [rejected]        main -> main (remote ref updated since checkout)
error: failed to push some refs to '../origin.git'

$ git reset --hard HEAD~1
HEAD is now at 57d1928 commit B
$ git reflog -n 3
57d1928 HEAD@{0}: reset: moving to HEAD~1
a508fb0 HEAD@{1}: commit: commit C
57d1928 HEAD@{2}: commit: commit B
$ git reset --hard HEAD@{1}
HEAD is now at a508fb0 commit C

$ git commit --amend -m "commit C (fixed message)"
$ git reflog -n 2
9e715fe HEAD@{0}: commit (amend): commit C (fixed message)
a508fb0 HEAD@{1}: reset: moving to HEAD

$ git reset --hard HEAD~1
HEAD is now at 57d1928 commit B
$ git reset --hard ORIG_HEAD
HEAD is now at a508fb0 commit C

$ echo "staged only content" > lost.txt
$ git add lost.txt
$ git reset --hard
HEAD is now at a508fb0 commit C
$ git fsck --lost-found
dangling blob 594d2a13b62c67be0df3722830533d098a1b233a
$ cat .git/lost-found/other/594d2a13b62c67be0df3722830533d098a1b233a
staged only content