D542: effectflag: document effect flag

[quark (Jun Wu)]

quark added a comment.


  As I commented earlier in an email thread. I think it's cleaner to record a hash of patch to detect content change, so we will be able to detect undos:
  
  A -- amend --> B -- unamend --> C
  
  When asking the difference between A and C, we can answer "no change".
  
  I also think other chnages like meta, parent, user, data should be calculated directly from changelog because changelog is fast. You may argue that obsstore may have nodes unknown to chnagelog but I don't think the end-user care about those nodes (since they cannot see the actual content of them).

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D542

To: lothiraldan, #hg-reviewers
Cc: quark, mercurial-devel