Now I'm still not sure I got everything straight in my head:
The HG wiki says "Git, by contrast, has "branches" that are not stored in history, which is useful for working with numerous short-lived feature branches, but makes future auditing impossible."
Git branches are just commits on a separate path in the tree, right? As long as the branch is merged with git merge --no-ff (which can't be set as the default, yes, I know) -- then a git branch becomes a permanent part of the history due to the commit created during the merge. The fast-forward option is just that: optional. It's only useful as a history-rewriting tool, kind of the way git squash is useful.
I guess I'm asking, what does the HG wiki mean, in concrete terms? What is impossible with git?
Also, to be sure I understood the original comment well, I'll try to sum up the difference between HG branches and bookmarks. Is it correct?
HG branches copy-on-write the entire source tree. This means a HG branch cannot be changed if the history before the branch changes. HG bookmarks (and git branches) can change later if the history changes.
Nothing is impossible, it works like you described. In very simple terms, following Git philosophy rewriting history is a feature, according to HG it's a bug (technically, it is somehow possible AFAIK, but not sure if it's used around for anything except critical fix scenarios). It's just that. Hence the term 'branch' in HG refers to something permanent and 'bookmarks' provide the lightweight functionality. At its roots they have a different approach to managing history (back when I used HG more I didn't understand all the noise around rewriting Git history, obsession with keeping it clean and linear, etc.).
I looked at http://mercurial.selenic.com/wiki/Bookmarks/ (I already have a pretty good understanding of HG branches.)
Now I'm still not sure I got everything straight in my head:
The HG wiki says "Git, by contrast, has "branches" that are not stored in history, which is useful for working with numerous short-lived feature branches, but makes future auditing impossible."
Git branches are just commits on a separate path in the tree, right? As long as the branch is merged with git merge --no-ff (which can't be set as the default, yes, I know) -- then a git branch becomes a permanent part of the history due to the commit created during the merge. The fast-forward option is just that: optional. It's only useful as a history-rewriting tool, kind of the way git squash is useful.
I guess I'm asking, what does the HG wiki mean, in concrete terms? What is impossible with git?
Also, to be sure I understood the original comment well, I'll try to sum up the difference between HG branches and bookmarks. Is it correct?
HG branches copy-on-write the entire source tree. This means a HG branch cannot be changed if the history before the branch changes. HG bookmarks (and git branches) can change later if the history changes.