Extra lines in commit comment changes the commit hash - breaks hg-git interoperability

[drandreasdr]

Hi!

I just converted a Mercurial repo to git via git-remote-hg, and I get different commit hashes compared to the last time I converted the repo, 1-2 years ago.

• The git hashes are identical for the first hundred commits or so.
• Then, at one point, git-remote-hg apparently introduces a few extra lines in the commit comment (prefixed by --HG--). This makes the commit hash different for that particular commit.
• Every commit after that point now differs (understandably, since hashes are generated based on information in the parent commit)
• This obviously breaks inoperability, and is a serious blocker for my work.

Comparison of git log output for the converted repo, for the repo converted a few years ago (left) and the one converted today (right):

The original mercurial commit looks like this: (where I hope you'll excuse me obscuring some sensitive information)

I can see in the git-remote-hg source code when and why this extra text in the comment (prefixed by --HG--) is added. But I'm puzzled as to why this text is absent in the git repo that I converted a few years ago, and present in the one I converted today.

Do you know of any setting, configuration, or version discrepancy that could explain this difference? Do you have any recommendations for how I could achieve a one-to-one hg->git conversion such that I can preserve interoperability?

Best Regards, Andreas

[drandreasdr]

Ah, I just figured it out. This setting in my ~/.gitconfig was causing the problem:

[remote-hg]
hg-git-compat = true

Setting it to false solved the problem. Closing the issue, and hoping that it can help someone else.

[felipec]

@drandreasdr Yes, you probably converted it initially with hg-git.