Revert "consensus: correctly save reference to previous height precom…

…mits (backport #9760) (#9775)" (#9945)

This reverts commit 5703cc3.

CHANGELOG_PENDING.md

@@ -46,7 +46,6 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 - [proto] \#9356 Migrate from `gogo/protobuf` to `cosmos/gogoproto` (@julienrbrt)
 - [rpc] \#9276 Added `header` and `header_by_hash` queries to the RPC client (@samricotta)
 - [abci] \#5706 Added `AbciVersion` to `RequestInfo` allowing applications to check ABCI version when connecting to Tendermint. (@marbar3778)
-- [consensus] \#9760 Save peer LastCommit correctly to achieve 50% reduction in gossiped precommits. (@williambanfield)
 
 ### BUG FIXES
 

consensus/reactor.go

@@ -1294,7 +1294,6 @@ func (ps *PeerState) ApplyNewRoundStepMessage(msg *NewRoundStepMessage) {
 	psRound := ps.PRS.Round
 	psCatchupCommitRound := ps.PRS.CatchupCommitRound
 	psCatchupCommit := ps.PRS.CatchupCommit
-	lastPrecommits := ps.PRS.Precommits
 
 	startTime := tmtime.Now().Add(-1 * time.Duration(msg.SecondsSinceStartTime) * time.Second)
 	ps.PRS.Height = msg.Height
@@ -1322,7 +1321,7 @@ func (ps *PeerState) ApplyNewRoundStepMessage(msg *NewRoundStepMessage) {
 		// Shift Precommits to LastCommit.
 		if psHeight+1 == msg.Height && psRound == msg.LastCommitRound {
 			ps.PRS.LastCommitRound = msg.LastCommitRound
-			ps.PRS.LastCommit = lastPrecommits
+			ps.PRS.LastCommit = ps.PRS.Precommits
 		} else {
 			ps.PRS.LastCommitRound = msg.LastCommitRound
 			ps.PRS.LastCommit = nil