为什么git浅克隆可以有比<depth>更多的提交？

Question

git clone --depth <depth> <url> <repo>; git -C <repo> rev-list --count --all != <depth>

git clone --depth <depth>:创建一个具有截断为<depth> 提交的历史记录的克隆.意味着--single-branch.

例如:url = https://github.com/vhf/free-programming-books.git,depth = 10,然后commit_count = 15

git version 2.9.0

Answer 1

存储库的浅版本包括在跟随所有可能的父级而不是仅跟随第一个父级时,在距离分支头指定距离内的所有提交.因此,对于具有合并的非线性历史记录,提交计数将不等于深度.

$ git clone --depth 10 https://github.com/vhf/free-programming-books.git
Cloning into 'free-programming-books'...
remote: Counting objects: 85, done.
remote: Compressing objects: 100% (63/63), done.
remote: Total 85 (delta 31), reused 46 (delta 22), pack-reused 0
Unpacking objects: 100% (85/85), done.
Checking connectivity... done.

$ git -C free-programming-books/ rev-list --count HEAD
15

$ git -C free-programming-books/ log --graph --oneline --decorate
* b9ffc8e (HEAD -> master, origin/master, origin/HEAD) Adding pt_BR C book used by ...
* 824c1d3 Replaced Google Python style guide dead-link with new one (#1987)
* 3c32612 Added Laravel: Code Smart online book (#1986)
* eabce2c Fixed typo: Structure and Interpretation (#1985)
* aab83e5 Added IRPF90 gitbook to Misc section (#1984)
* 6f72509 Added a bash tutorial in free-courses-en.md (#1983)
*   9b95b09 Merge branch 'pr/1980'
|\  
| * 2811cd3 Fix blank lines
| * bbe9bd6 Adds 2 golang podcasts (and fixes missing #ggulp)
| * fdeabc6 (grafted) Fix ordering
*   da317ad Merge branch 'pr/1976'
|\  
| * 20b940a Fix ordering
| * 9a6ee0b (grafted) Add openHPI to list of MOOCs
* 43294d1 Update link Rust by Example #1970 (#1995)
* d758a93 (grafted) Fix a broken link to 'Practical PostgreSQL' (#1994)

在这个截断历史伪根提交的d758a93,9a6ee0b和fdeabc6.他们都是头部提交的第9代祖先.

原始答案(提供MVCE之前)

当<url>没有开始时,本地克隆可能就是这种情况file://.然后git输出相应的警告:

warning: --depth is ignored in local clones; use file:// instead.

对于本地克隆,git只是创建源存储库中对象的硬链接(除非--no-hardlinks指定了开关,但后者仍然不会使本地克隆尊重该--depth选项).通过硬链接进行克隆可以节省磁盘空间,与复制所有对象相比,速度非常快.由于该--depth选项的目的是减少数据传输,因此对本地克隆没有多大意义,因此被忽略.