commit 107c2e025afdef50a60974b91a35e0bba3fd7e51
author Edwin Kempin <ekempin@google.com> Thu Nov 24 15:01:31 2022 +0100
committer Edwin Kempin <ekempin@google.com> Tue Nov 29 13:13:10 2022 +0100
tree eacccfaeb7a75a2059ac531cf8e92e616d5f5a1b
parent 3e04849335a632b1d3f298ae731ecfe90d8a4a69

Include copied votes into change message when voting on outdated patch set

Since change I4d9b71616 votes that are applied on outdated patch sets
are copied to follow-up patch sets if possible (follow-up patch sets are
all patch sets that are newer than the outdated patch set on which the
vote was applied). When votes are copied to follow-up patch sets they
are applied in NoteDb, but users are not informed about them. This means
if a vote is applied on an outdated patch set and is then copied forward
to follow-up patch sets, including the current patch set, users can see
the copied vote on the change, but they can't find out how it appeared
there.

With this change we are now informing in the change message that is
posted when a vote is applied on an outdated patch set about the
follow-up patch sets to which the vote is copied forward. In other words
we are extending the existing change message that informs about the user
vote on the outdated patch set with information about the copied votes
on the follow-up patch sets that have been updated as result of the user
voting on the outdated patch set.

Informing the user about the follow-up patch sets that have been updated
as result of the user voting on the outdated patch set via the change
message is consistent with how we inform users about copied votes when a
new patch set is created (also in this case we post this information as
a change message).

When the user votes on an outdated patch sets there are 3 possibilities
how copied votes on follow-up patch sets are updated:

1. a copied approval is added on a follow-up patch set (no copied
   approval existing on this patch set yet)
2. an existing copied approval is updated on a follow-up patch set (e.g.
   if Code-Review-2 on PS1 was sticky and got copied to PS2, but now the
   vote on PS1 is changed to Code-Review+2 which is also sticky the
   copied vote on PS2 gets updated from Code-Review-2 to Code-Review+2)
3. an existing copied approval is removed from a follow-up patch set
   (example 1: if Code-Review-2 on PS1 was sticky and got copied to PS2,
   but now the vote on PS1 is changed to Code-Review-1 which is not
   sticky the existing copied vote on PS2 gets removed; example 2: if
   Code-Review-2 on PS1 was sticky and got copied to PS2, but now the
   vote on PS1 is removed the existing copied vote on PS2 gets removed)

Note: The approval copying that is done when a user votes on an outdated
patch set only affects copied approvals on follow-up patch sets, but
never non-copied approvals nor explicit approval deletions.

The existing change message already informs about the user action (which
vote was applied on which patch sets), e.g. "Patch Set 1:
Code-Review+2". In addition we include now information about the updates
on the follow-up patch sets.

If label votes have been copied to follow-up patch sets (case 1.) the
additional information in the change message is:

  * <label-vote> has been copied to patch sets: 3, 4 (copy condition:
    "<copy-condition>").

If existing copied votes on follow-up patch sets have been updated
(case 2.), the old copied votes are included into the message:

  * <label-vote> has been copied to patch sets:
    3 (was <old-label-vote>), 4 (was <old-label-vote>) (copy condition:
    "<copy-condition>").

If existing copied votes on follow-up patch sets have been removed
(e.g. because the new vote is not copyable) (case 3.) the message is:

  * Copied <label> vote has been removed from patch set 3 (was
    <old-label-vote>), 4 (was <old-label-vote>) (copy condition:
    "<copy-condition>").

If copied votes have been both added/updated and removed, 2 messages are
included:

  * <label-vote> has been copied to patch sets:
    3 (was <old-label-vote>), 4 (was <old-label-vote>) (copy condition:
    "<copy-condition>").
  * Copied <label> vote has been removed from patch set 5 (was
    <old-label-vote>) (copy condition: "<copy-condition>").

Passing atoms in copy conditions are not highlighted. This is because
the passing atoms can be different for different follow-up patch sets
(e.g. 'changekind:TRIVIAL_REBASE OR changekind:NO_CODE_CHANGE' can have
'changekind:TRIVIAL_REBASE' passing for one follow-up patch set and
'changekind:NO_CODE_CHANGE' passing for another follow-up patch set).
Including the copy condition once per follow-up patch set with
differently highlighted passing atoms would make the message unreadable.
Hence we don't highlight passing atoms here.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I7ca035f668ce5dadc8403ebe9195a3aac27e354d
Bug: Google b/235818646
Release-Notes: Votes that are copied to follow-up patch sets when a vote on an outdated patch set is applied are now posted as a change message.