strip extensions in blocksync

internal/blocksync/reactor.go

@@ -560,6 +560,8 @@ func (r *Reactor) poolRoutine(ctx context.Context, stateSynced bool, blockSyncCh
 			if err == nil && state.ConsensusParams.ABCI.VoteExtensionsEnabled(extCommit.Height) {
 				// if vote extensions were required at this height, ensure they exist.
 				err = extCommit.EnsureExtensions()
+			} else if err == nil && !state.ConsensusParams.ABCI.VoteExtensionsEnabled(extCommit.Height) {
+				extCommit.StripExtensions()
 			}
 			// If either of the checks failed we log the error and request for a new block
 			// at that height

internal/blocksync/reactor_test.go

@@ -155,7 +155,7 @@ func (rts *reactorTestSuite) addNode(
 	for blockHeight := int64(1); blockHeight <= maxBlockHeight; blockHeight++ {
 		lastExtCommit = seenExtCommit.Clone()
 
-		thisBlock := sf.MakeBlock(state, blockHeight, lastExtCommit.StripExtensions())
+		thisBlock := sf.MakeBlock(state, blockHeight, lastExtCommit.ToCommit())
 		thisParts, err := thisBlock.MakePartSet(types.BlockPartSizeBytes)
 		require.NoError(t, err)
 		blockID := types.BlockID{Hash: thisBlock.Hash(), PartSetHeader: thisParts.Header()}