[pitkali]

I don't think the internal design is/was that similar. We switched from CVS to git, and were evaluating multiple choices. What tipped the scale in the end was our trust in the internal data model, which for git was the idea that it stores the snapshots, and they are immutable. The diffs you can get out of it are calculated on demand. Even if on-disk storage can end up using some diffs to save on space, the actual conceptual model of every operation is based on those snapshots, and that is also how every new commit is stored before repacking the repository.

This appealed greatly to us, and always meant that it is effortless to undo any operation because it only creates new snapshots, while the previous ones stay there for a while in case you need to recover the previous state.

This is in contrast with Mercurial, where the data store is (was?) a sequence of diffs, and then the state of the working tree at any time is reconstructed on demand from those diffs.