types: refactor PB2TM.ConsensusParams to take BlockTimeIota as an arg (#3442)

See https://github.com/tendermint/tendermint/pull/3403/files#r266208947

In #3403 we unexposed BlockTimeIota from the ABCI, but it's still part
of the ConsensusParams struct, so we have to remember to add it back
after calling PB2TM.ConsensusParams. Instead, PB2TM.ConsensusParams
should take it as an argument

Fixes #3432

consensus/replay.go

@@ -324,12 +324,7 @@ func (h *Handshaker) ReplayBlocks(
 			}
 
 			if res.ConsensusParams != nil {
-				// Preserve TimeIotaMs since it's not exposed to the application.
-				timeIotaMs := state.ConsensusParams.Block.TimeIotaMs
-				{
-					state.ConsensusParams = types.PB2TM.ConsensusParams(res.ConsensusParams)
-				}
-				state.ConsensusParams.Block.TimeIotaMs = timeIotaMs
+				state.ConsensusParams = types.PB2TM.ConsensusParams(res.ConsensusParams, state.ConsensusParams.Block.TimeIotaMs)
 			}
 			sm.SaveState(h.stateDB, state)
 		}

types/protobuf.go

@@ -221,7 +221,9 @@ func (pb2tm) ValidatorUpdates(vals []abci.ValidatorUpdate) ([]*Validator, error)
 	return tmVals, nil
 }
 
-func (pb2tm) ConsensusParams(csp *abci.ConsensusParams) ConsensusParams {
+// BlockParams.TimeIotaMs is not exposed to the application. Therefore a caller
+// must provide it.
+func (pb2tm) ConsensusParams(csp *abci.ConsensusParams, blockTimeIotaMs int64) ConsensusParams {
 	params := ConsensusParams{
 		Block:     BlockParams{},
 		Evidence:  EvidenceParams{},
@@ -231,8 +233,9 @@ func (pb2tm) ConsensusParams(csp *abci.ConsensusParams) ConsensusParams {
 	// we must defensively consider any structs may be nil
 	if csp.Block != nil {
 		params.Block = BlockParams{
-			MaxBytes: csp.Block.MaxBytes,
-			MaxGas:   csp.Block.MaxGas,
+			MaxBytes:   csp.Block.MaxBytes,
+			MaxGas:     csp.Block.MaxGas,
+			TimeIotaMs: blockTimeIotaMs,
 		}
 	}
 

types/protobuf_test.go

@@ -64,9 +64,7 @@ func TestABCIValidators(t *testing.T) {
 func TestABCIConsensusParams(t *testing.T) {
 	cp := DefaultConsensusParams()
 	abciCP := TM2PB.ConsensusParams(cp)
-	cp2 := PB2TM.ConsensusParams(abciCP)
-	// TimeIotaMs is not exposed to the application.
-	cp2.Block.TimeIotaMs = cp.Block.TimeIotaMs
+	cp2 := PB2TM.ConsensusParams(abciCP, cp.Block.TimeIotaMs)
 
 	assert.Equal(t, *cp, cp2)
 }