[LLVMdev] Request: Changing commit message in llvm trunk

[James Y Knight]

On Jul 28, 2015, at 9:34 PM, Nick Lewycky <nicholas at mxc.ca> wrote:
> Anton Korobeynikov wrote:
>>> It could be very useful for 3 reason.
>> This will surely break git mirrors.
> Sounds like the git mirror's problem.


I don't think the git mirror would be *terribly* broken, it'd just never see the commit message change. But, the annoying part would be if/when someone recreated the git mirror, as it would then contain the new commit message, and thus that commit and all subsequent commits would have a different commit-hash.

This will similarly "break" anyone's svn mirrors (e.g. done by svnsync), as it cannot automatically detect that a commit message has been updated. If you were paying attention, you could copy the new data via svnsync copy-revprops, but that basically requires manual interaction.

Independently of those particular breakages, it's just a terrible idea to allow unversioned modifications to be made to the version control's historical record. That's the kind of thing that should only ever be done in truly exceptional cases by a repository admin.

-1 to ever enabling revprop changes.