They don't maintain the branch name, or even the history of the branch: they just tell what are the parent commits of the commit; as mentioned above, this history can be a "lie". Fossil's history is immutable — once the commit is there, it's there forever (although you can prevent an artifact from being synched or displayed with "shunning").
That's not a proper data structure, and you can't point to a random commit after merging and deleting a branch, and ask git to tell you which branch it came from.
Yes, you can. The name is not stored in the history other than the merge commit message but the full history is there and you can ask git to show you the merge commit for any commit.
No I'm not, you do _not_ require keeping a branch around to have the complete commit history of the branch, the point it diverged from another branch, all the commits that were on the branch, and the point where it was merged back into another branch. Git doesn't keep the name of the branch in the history outside the merge commit message, but everything else is there.
- Eve has a repository, Alice and Bob have access to it. Eve goes on vacation and nobody commits to "master"/"trunk".
- Alice makes a branch "alice-fixes" and creates commits on it.
- Bob comes and creates a branch "bob-features" from some point from "alice-fixes".
- Bob then merges "bob-features" into "master" and deletes it.
- Alice gets fired and her branch is deleted without merging.
In git, you can't see that some of the commits in the history came from "alice-fixes". Fossil, on the other keeps track of branch names and _changes_ in commits:
When Alice created her branch: -trunk +alice-fixes
When Bob created his branch: -alice-fixes +blob-features
When Bob merges his branch: -bob-features +trunk
You can't delete this information, because it's recorded in the commit artifacts. You can't delete branches — you can only close and hide them (you can also apply edits to commits by adding "edit" artifacts [don't remember what the are called], but the history is preserved, not modified.)
I think that is just an example of losing the branch name, the commit history is the same in both cases.
If you really want that behavior from git, you can have it, just create a tag for each branch HEAD. Actually I think this is all that fossil does as well.
It's not the same, there's no commit indicating that Bob branched off Alice's branch. It appears as if the whole history before merging belongs to Bob's branch. There is such commit in Fossil.
> If you really want that behavior from git, you can have it, just create a tag for each branch HEAD. Actually I think this is all that fossil does as well.
Fossil has branch/tag name directly in the checkin manifest (I've linked to the document describing file format somewhere above.) Tag and branch names are embedded directly in the history, they are not separate references to commit hashes like in git.
