[PATCH] obsolete: add operation metadata to rebase/amend/histedit obsmarkers

[Jun Wu]

Excerpts from Gregory Szorc's message of 2017-05-19 09:51:46 -0700:
> > I agree with Pierre-Yves that the bit-based solution seems better
> > long-term. I'm not particularly worried about wasting bits. I was also
> > happy for Durham's patch as a short-term solution. But since
> > Pierre-Yves et al are already working on the bit-based solution, I'd
> > prefer to give them at least a month to make progress on that.
> 
> Perfect is the enemy of done.
> 
> If we're really uncomfortable with the strings, we can put that behind an
> experimental config or requirement so we don't pollute real repos. Then we
> can figure out something before 4.3. At least this way something lands and
> some progress is made (even if the exact implementation doesn't pan out).

Talking about perfection, I also don't think the 3 bits: parent-change,
content-change and metadata-change is a good abstraction.

Because they are redundant data. They can be calculated afterwards, in a
cache. Having them in obsstore means we could have inconsistency - changelog
disagrees with obsstore about the flags (data written by some bad
extensions) - how would you deal with that?

"operation" metadata is not redundant - you cannot get them from elsewhere
so they should be recorded.