tree 1cb3f03eb6e8392bdfbe8b506bdf75d2d40f9383
parent 83635c3710fd4c9ec0384b63a738b6d87b947f6b
author Patrick Hiesel <hiesel@google.com> 1560851261 +0200
committer Patrick Hiesel <hiesel@google.com> 1560862772 +0200

Fix ReceiveCommitsAdvertiseRefsHook, add docs and test coverage

The tests for receive commits ref advertising were further away from
reality than they should have been. In essence, they tested
ReceiveCommitsAdvertiseRefsHook directly, which let room for bugs to
creep in.

Most prominently, we filter metadata for pushes. As metadata we see
refs/changes/* and refs/cache-automerge/* (suboptimal naming is a
concern not addressed by this commit).

When the previous ref filter has already filtered out change refs
then ReceiveCommitsAdvertiseRefsHook became a no-op and did not
advertise the additional .haves it should because of a check for
existence based on the previously advertised refs.

This commit:
 - Fixes the aforementioned bug
 - Brings tests closer to reality by including the whole advertising
   chain, have JGit do the actual advertising and assert on that
 - Document the desired behavior

Change-Id: I230e66eee5b94c6f62b0426e5c16849d993a1cfe