git log -all显示使用filter-branch删除的提交

Question

To remove everything that is not "my_dir/" in my repository history I used:

git filter-branch --prune-empty --subdirectory-filter my_dir/  --prune-empty --tag-name-filter cat -- --all
git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d;
git reflog expire --expire=now --all;
git gc --prune=now;

Now, using:

git log

everything seems fine: the log only shows commits containing files in "my_dir".

But:

git log --all

still shows everything. In fact, doing another filter-branch (to remove some other .pyc files in my_dir) will find (and remove) all the .pyc files in the old dirs.

It seems that --subdirectory-filter doesn't really remove the commits... they are still there.

What am I missing?

EDIT:

subdirectory-filter "only look at the history which touches the given subdirectory". So maybe it doesn't remove all the other commits, but just rewrites the ones that touch that dir and somehow leaves "orphans" for the others???

Answer 1

The filter-branch command creates new refs to the "old" commits in case you need to undo. git log --all shows the history of all refs, including the special refs that filter-branch created.

More generally, the only git command (I can think of) that will actually delete a commit object is gc . For gc to remove a commit, it must not be reachable from any ref or from the reflog. So if you want the commits to be really gone:

1) Delete the original/* refs

2) Wipe out the reflog

3) run an aggressive gc with prune=now