Extract an ApprovalCopier from ApprovalsUtil
Rewrite in such a way that we can do an implicit "copy" between
arbitrary patch sets without necessarily storing the results. For the
notedb, we will use this (with cached ChangeKinds) rather than storing
copied labels.
This introduces a few minor behavior changes. First, copied approvals
are now normalized according to permissions. This may result in
different values stored in the database when copying, but these values
were already normalized out by ChangeJson and the submit rule
evaluator, so this should not result in a semantic change.
Second, we no longer pass in a "source" patch set; all prior patch
sets are considered. This has the advantage that it does not rely on
labels having been properly copied to intermediate patch sets. It also
means, for example, if patch set 3 has a code change relative to patch
set 2 but not patch set 1, approvals on a copyAllScoresOnNoCodeChange
label will be copied from patch set 1, bypassing patch set 2. We think
this is a more correct state of affairs: if patch set 1 is good enough
to submit, so should patch set 3, regardless of the fact that there is
an intermediate patch set.
Change-Id: I56ae707c34ac7b978b06a0624c1353e8f28286a7
5 files changed
