From b02f9b6141627127acd027ed9491dd7c0ca5dd2a Mon Sep 17 00:00:00 2001 From: Nick Thomas Date: Wed, 24 Jan 2018 15:06:50 +0000 Subject: Look at notes created just before merge when deciding if an MR can be reverted On MySQL, at least, `Note#created_at` doesn't seem to store fractional seconds, while `MergeRequest::Metrics#merged_at` does. This breaks the optimization assumption that we only need to search for notes created *after* the MR has been merged. Unsynchronized system clocks also make this a dangerous assumption to make. Adding a minute of leeway still optimizes away most notes, but allows both cases to be handled more gracefully. If the system clocks are more than a minute out, we'll still be broken, of course. --- app/models/merge_request.rb | 8 +++++++- spec/models/merge_request_spec.rb | 14 ++++++++++++-- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb index 8028ff3875b..4accb08eaf9 100644 --- a/app/models/merge_request.rb +++ b/app/models/merge_request.rb @@ -989,8 +989,14 @@ class MergeRequest < ActiveRecord::Base merged_at = metrics&.merged_at notes_association = notes_with_associations + # It is not guaranteed that Note#created_at will be strictly later than + # MergeRequestMetric#merged_at. Nanoseconds on MySQL may break this + # comparison, as will a HA environment if clocks are not *precisely* + # synchronized. Add a minute's leeway to compensate for both possibilities + cutoff = merged_at - 1.minute + if merged_at - notes_association = notes_association.where('created_at > ?', merged_at) + notes_association = notes_association.where('created_at >= ?', cutoff) end !merge_commit.has_been_reverted?(current_user, notes_association) diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb index c76f32b3989..429b6615131 100644 --- a/spec/models/merge_request_spec.rb +++ b/spec/models/merge_request_spec.rb @@ -1127,9 +1127,19 @@ describe MergeRequest do end end - context 'when the revert commit is mentioned in a note before the MR was merged' do + context 'when the revert commit is mentioned in a note just before the MR was merged' do before do - subject.notes.last.update!(created_at: subject.metrics.merged_at - 1.second) + subject.notes.last.update!(created_at: subject.metrics.merged_at - 30.seconds) + end + + it 'returns false' do + expect(subject.can_be_reverted?(current_user)).to be_falsey + end + end + + context 'when the revert commit is mentioned in a note long before the MR was merged' do + before do + subject.notes.last.update!(created_at: subject.metrics.merged_at - 2.minutes) end it 'returns true' do -- cgit v1.2.1