| 中文文章 | English article |
实验在一个新建临时根目录中创建一个 bare origin.git 和两个 clone：reader、writer。所有 push 都指向这个临时 bare 仓库，不读取当前项目的 remote，也不读取全局 Git 配置、签名设置或本机 hooks。
lab_path=$(bash setup.sh)
bash verify.sh "$lab_path"
sed -n '1,240p' "$lab_path/observations.txt"
sed -n '1,240p' "$lab_path/push-results.txt"
bash cleanup.sh "$lab_path"
fetch 后，reader 的 origin/main 从 A 变为 B，main、Index 和 Working Tree 保持 A。随后实验显式执行 merge --ff-only origin/main，再断言这三处变为 B。两个 clone 后续各自产生提交，reader 向已前进的 bare origin push 会被 Git 拒绝。实验还安装了一个只拒绝 protected 分支的 bare-repo hook，用于演示服务器端策略可以拒绝客户端请求；它不模拟托管平台的真实身份认证。
cleanup.sh 只接受带本实验标记、且结构完整的临时根目录。希望保留现场时跳过 cleanup，完成观察后再执行它。
一次运行完整自测：
bash test.sh
The lab creates a new temporary root containing a bare origin.git and two clones, reader and writer. Every push targets that temporary bare repository. It does not read this project’s remote, global Git configuration, signing settings, or local hooks.
lab_path=$(bash setup.sh)
bash verify.sh "$lab_path"
sed -n '1,240p' "$lab_path/observations.txt"
sed -n '1,240p' "$lab_path/push-results.txt"
bash cleanup.sh "$lab_path"
After fetch, reader moves origin/main from A to B while its main, index, and working tree remain at A. The lab then explicitly runs merge --ff-only origin/main and asserts that all three move to B. The two clones subsequently create separate commits, and Git rejects reader’s push to the bare origin after it has advanced. The lab also installs a bare-repository hook that rejects only the protected branch. It demonstrates that server-side policy can reject a client request; it does not emulate hosted-service authentication.
cleanup.sh accepts only a marked, structurally complete lab root. Skip cleanup while inspecting the evidence, then run it when finished.
Run the complete self-test:
bash test.sh