multi: Simplify code per gosimple linter.

This simplifies the code based on the recommendations of the gosimple
lint tool.

addrmgr/addrmanager_test.go

@@ -258,7 +258,7 @@ func TestNeedMoreAddresses(t *testing.T) {
 	n := addrmgr.New("testneedmoreaddresses", lookupFunc)
 	addrsToAdd := 1500
 	b := n.NeedMoreAddresses()
-	if b == false {
+	if !b {
 		t.Errorf("Expected that we need more addresses")
 	}
 	addrs := make([]*wire.NetAddress, addrsToAdd)
@@ -287,7 +287,7 @@ func TestNeedMoreAddresses(t *testing.T) {
 	}
 
 	b = n.NeedMoreAddresses()
-	if b == true {
+	if b {
 		t.Errorf("Expected that we don't need more addresses")
 	}
 }

blockchain/chain.go

@@ -1527,14 +1527,11 @@ func (b *BlockChain) IsCurrent() bool {
 
 	// Not current if the latest best block has a timestamp before 24 hours
 	// ago.
-	minus24Hours := b.timeSource.AdjustedTime().Add(-24 * time.Hour)
+	//
-	if b.bestNode.timestamp.Before(minus24Hours) {
+	// The chain appears to be current if none of the checks reported
-		return false
-	}
-
-	// The chain appears to be current if the above checks did not report
 	// otherwise.
-	return true
+	minus24Hours := b.timeSource.AdjustedTime().Add(-24 * time.Hour)
+	return !b.bestNode.timestamp.Before(minus24Hours)
 }
 
 // BestSnapshot returns information about the current best chain block and

blockchain/chain_test.go

@@ -31,9 +31,7 @@ func TestHaveBlock(t *testing.T) {
 			t.Errorf("Error loading file: %v\n", err)
 			return
 		}
-		for _, block := range blockTmp {
+		blocks = append(blocks, blockTmp...)
-			blocks = append(blocks, block)
-		}
 	}
 
 	// Create a new database and chain instance to run tests against.
@@ -119,15 +117,11 @@ func TestHaveBlock(t *testing.T) {
 // the returned SequenceLocks are correct for each test instance.
 func TestCalcSequenceLock(t *testing.T) {
 	fileName := "blk_0_to_4.dat.bz2"
-	blockTmp, err := loadBlocks(fileName)
+	blocks, err := loadBlocks(fileName)
 	if err != nil {
 		t.Errorf("Error loading file: %v\n", err)
 		return
 	}
-	var blocks []*btcutil.Block
-	for _, block := range blockTmp {
-		blocks = append(blocks, block)
-	}
 
 	// Create a new database and chain instance to run tests against.
 	chain, teardownFunc, err := chainSetup("haveblock", &chaincfg.MainNetParams)

blockchain/indexers/manager.go

@@ -271,10 +271,7 @@ func (m *Manager) Init(chain *blockchain.BlockChain) error {
 		err := m.db.View(func(dbTx database.Tx) error {
 			idxKey := indexer.Key()
 			hash, height, err = dbFetchIndexerTip(dbTx, idxKey)
-			if err != nil {
+			return err
-				return err
-			}
-			return nil
 		})
 		if err != nil {
 			return err

blockchain/reorganization_test.go

@@ -39,9 +39,7 @@ func TestReorganization(t *testing.T) {
 		if err != nil {
 			t.Errorf("Error loading file: %v\n", err)
 		}
-		for _, block := range blockTmp {
+		blocks = append(blocks, blockTmp...)
-			blocks = append(blocks, block)
-		}
 	}
 
 	t.Logf("Number of blocks: %v\n", len(blocks))

blockchain/scriptval.go

@@ -213,11 +213,7 @@ func ValidateTransactionScripts(tx *btcutil.Tx, utxoView *UtxoViewpoint, flags t
 
 	// Validate all of the inputs.
 	validator := newTxValidator(utxoView, flags, sigCache)
-	if err := validator.Validate(txValItems); err != nil {
+	return validator.Validate(txValItems)
-		return err
-	}
-
-	return nil
 }
 
 // checkBlockScripts executes and validates the scripts for all transactions in
@@ -248,9 +244,5 @@ func checkBlockScripts(block *btcutil.Block, utxoView *UtxoViewpoint, scriptFlag
 
 	// Validate all of the inputs.
 	validator := newTxValidator(utxoView, scriptFlags, sigCache)
-	if err := validator.Validate(txValItems); err != nil {
+	return validator.Validate(txValItems)
-		return err
-	}
-
-	return nil
 }

btcjson/help.go

@@ -122,9 +122,7 @@ func resultStructHelp(xT descLookupFunc, rt reflect.Type, indentLevel int) []str
 			result := fmt.Sprintf("%s\"%s\": %s\t(%s)\t%s", indent,
 				fieldName, brace, fieldType, xT(fieldDescKey))
 			results = append(results, result)
-			for _, example := range fieldExamples {
+			results = append(results, fieldExamples...)
-				results = append(results, example)
-			}
 		} else {
 			result := fmt.Sprintf("%s\"%s\": %s,\t(%s)\t%s", indent,
 				fieldName, fieldExamples[0], fieldType,

database/cmd/dbtool/fetchblock.go

@@ -50,7 +50,7 @@ func (cmd *fetchBlockCmd) Execute(args []string) error {
 		if err != nil {
 			return err
 		}
-		log.Infof("Loaded block in %v", time.Now().Sub(startTime))
+		log.Infof("Loaded block in %v", time.Since(startTime))
 		log.Infof("Block Hex: %s", hex.EncodeToString(blockBytes))
 		return nil
 	})

database/cmd/dbtool/fetchblockregion.go

@@ -77,7 +77,7 @@ func (cmd *blockRegionCmd) Execute(args []string) error {
 		if err != nil {
 			return err
 		}
-		log.Infof("Loaded block region in %v", time.Now().Sub(startTime))
+		log.Infof("Loaded block region in %v", time.Since(startTime))
 		log.Infof("Double Hash: %s", chainhash.DoubleHashH(regionBytes))
 		log.Infof("Region Hex: %s", hex.EncodeToString(regionBytes))
 		return nil

database/cmd/dbtool/insecureimport.go

@@ -121,10 +121,7 @@ func (bi *blockImporter) processBlock(serializedBlock []byte) (bool, error) {
 	var exists bool
 	err = bi.db.View(func(tx database.Tx) error {
 		exists, err = tx.HasBlock(block.Hash())
-		if err != nil {
+		return err
-			return err
-		}
-		return nil
 	})
 	if err != nil {
 		return false, err
@@ -139,10 +136,7 @@ func (bi *blockImporter) processBlock(serializedBlock []byte) (bool, error) {
 		var exists bool
 		err := bi.db.View(func(tx database.Tx) error {
 			exists, err = tx.HasBlock(prevHash)
-			if err != nil {
+			return err
-				return err
-			}
-			return nil
 		})
 		if err != nil {
 			return false, err

database/cmd/dbtool/loadheaders.go

@@ -62,14 +62,10 @@ func (cmd *headersCmd) Execute(args []string) error {
 				return nil
 			})
 			log.Infof("Loaded %d headers in %v", numLoaded,
-				time.Now().Sub(startTime))
+				time.Since(startTime))
 			return nil
 		})
-		if err != nil {
+		return err
-			return err
-		}
-
-		return nil
 	}
 
 	// Bulk load headers.
@@ -90,12 +86,8 @@ func (cmd *headersCmd) Execute(args []string) error {
 			return err
 		}
 		log.Infof("Loaded %d headers in %v", len(hdrs),
-			time.Now().Sub(startTime))
+			time.Since(startTime))
 		return nil
 	})
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }

database/ffldb/bench_test.go

@@ -29,10 +29,7 @@ func BenchmarkBlockHeader(b *testing.B) {
 	defer db.Close()
 	err = db.Update(func(tx database.Tx) error {
 		block := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
-		if err := tx.StoreBlock(block); err != nil {
+		return tx.StoreBlock(block)
-			return err
-		}
-		return nil
 	})
 	if err != nil {
 		b.Fatal(err)
@@ -73,10 +70,7 @@ func BenchmarkBlock(b *testing.B) {
 	defer db.Close()
 	err = db.Update(func(tx database.Tx) error {
 		block := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
-		if err := tx.StoreBlock(block); err != nil {
+		return tx.StoreBlock(block)
-			return err
-		}
-		return nil
 	})
 	if err != nil {
 		b.Fatal(err)

database/ffldb/dbcache.go

@@ -533,7 +533,7 @@ func (c *dbCache) flush() error {
 func (c *dbCache) needsFlush(tx *transaction) bool {
 	// A flush is needed when more time has elapsed than the configured
 	// flush interval.
-	if time.Now().Sub(c.lastFlush) > c.flushInterval {
+	if time.Since(c.lastFlush) > c.flushInterval {
 		return true
 	}
 
@@ -545,11 +545,7 @@ func (c *dbCache) needsFlush(tx *transaction) bool {
 	snap := tx.snapshot
 	totalSize := snap.pendingKeys.Size() + snap.pendingRemove.Size()
 	totalSize = uint64(float64(totalSize) * 1.5)
-	if totalSize > c.maxSize {
+	return totalSize > c.maxSize
-		return true
-	}
-
-	return false
 }
 
 // commitTx atomically adds all of the pending keys to add and remove into the

database/ffldb/interface_test.go

@@ -395,11 +395,7 @@ func testNestedBucket(tc *testContext, testBucket database.Bucket) bool {
 	defer func() {
 		tc.bucketDepth--
 	}()
-	if !testBucketInterface(tc, testBucket) {
+	return testBucketInterface(tc, testBucket)
-		return false
-	}
-
-	return true
 }
 
 // testBucketInterface ensures the bucket interface is working properly by
@@ -1504,11 +1500,7 @@ func testFetchBlockIO(tc *testContext, tx database.Tx) bool {
 	}
 	wantErrCode = database.ErrBlockRegionInvalid
 	_, err = tx.FetchBlockRegions(badBlockRegions)
-	if !checkDbError(tc.t, testName, err, wantErrCode) {
+	return checkDbError(tc.t, testName, err, wantErrCode)
-		return false
-	}
-
-	return true
 }
 
 // testBlockIOTxInterface ensures that the block IO interface works as expected
@@ -1942,11 +1934,7 @@ func testClosedTxInterface(tc *testContext, tx database.Tx) bool {
 		return false
 	}
 	err = tx.Commit()
-	if !checkDbError(tc.t, "closed tx commit", err, wantErrCode) {
+	return checkDbError(tc.t, "closed tx commit", err, wantErrCode)
-		return false
-	}
-
-	return true
 }
 
 // testTxClosed ensures that both the metadata and block IO API functions behave
@@ -2016,16 +2004,13 @@ func testConcurrecy(tc *testContext) bool {
 	startTime := time.Now()
 	err := tc.db.View(func(tx database.Tx) error {
 		_, err := tx.FetchBlock(tc.blocks[0].Hash())
-		if err != nil {
+		return err
-			return err
-		}
-		return nil
 	})
 	if err != nil {
 		tc.t.Errorf("Unexpected error in view: %v", err)
 		return false
 	}
-	elapsed := time.Now().Sub(startTime)
+	elapsed := time.Since(startTime)
 	if sleepTime < elapsed {
 		sleepTime = elapsed
 	}
@@ -2041,10 +2026,7 @@ func testConcurrecy(tc *testContext) bool {
 		err := tc.db.View(func(tx database.Tx) error {
 			time.Sleep(sleepTime)
 			_, err := tx.FetchBlock(tc.blocks[blockNum].Hash())
-			if err != nil {
+			return err
-				return err
-			}
-			return nil
 		})
 		if err != nil {
 			tc.t.Errorf("Unexpected error in concurrent view: %v",
@@ -2065,7 +2047,7 @@ func testConcurrecy(tc *testContext) bool {
 			return false
 		}
 	}
-	elapsed = time.Now().Sub(startTime)
+	elapsed = time.Since(startTime)
 	tc.t.Logf("%d concurrent reads of same block elapsed: %v", numReaders,
 		elapsed)
 
@@ -2088,7 +2070,7 @@ func testConcurrecy(tc *testContext) bool {
 			return false
 		}
 	}
-	elapsed = time.Now().Sub(startTime)
+	elapsed = time.Since(startTime)
 	tc.t.Logf("%d concurrent reads of different blocks elapsed: %v",
 		numReaders, elapsed)
 
@@ -2142,11 +2124,7 @@ func testConcurrecy(tc *testContext) bool {
 	// Set some data the readers are expecting to not find and signal the
 	// readers the write is done by closing the writeComplete channel.
 	err = tc.db.Update(func(tx database.Tx) error {
-		err := tx.Metadata().Put(concurrentKey, concurrentVal)
+		return tx.Metadata().Put(concurrentKey, concurrentVal)
-		if err != nil {
-			return err
-		}
-		return nil
 	})
 	if err != nil {
 		tc.t.Errorf("Unexpected error in update: %v", err)
@@ -2187,7 +2165,7 @@ func testConcurrecy(tc *testContext) bool {
 			return false
 		}
 	}
-	elapsed = time.Now().Sub(startTime)
+	elapsed = time.Since(startTime)
 	tc.t.Logf("%d concurrent writers elapsed using sleep time %v: %v",
 		numWriters, writeSleepTime, elapsed)
 

database/internal/treap/immutable_test.go

@@ -29,7 +29,7 @@ func TestImmutableEmpty(t *testing.T) {
 
 	// Ensure there are no errors with requesting keys from an empty treap.
 	key := serializeUint32(0)
-	if gotVal := testTreap.Has(key); gotVal != false {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -348,8 +348,8 @@ func TestImmutableDuplicatePut(t *testing.T) {
 		testTreap = testTreap.Put(key, expectedVal)
 
 		// Ensure the key still exists and is the new value.
-		if gotVal := testTreap.Has(key); gotVal != true {
+		if gotVal := testTreap.Has(key); !gotVal {
-			t.Fatalf("Has: unexpected result - got %v, want false",
+			t.Fatalf("Has: unexpected result - got %v, want true",
 				gotVal)
 		}
 		if gotVal := testTreap.Get(key); !bytes.Equal(gotVal, expectedVal) {
@@ -379,8 +379,8 @@ func TestImmutableNilValue(t *testing.T) {
 	testTreap = testTreap.Put(key, nil)
 
 	// Ensure the key exists and is an empty byte slice.
-	if gotVal := testTreap.Has(key); gotVal != true {
+	if gotVal := testTreap.Has(key); !gotVal {
-		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
+		t.Fatalf("Has: unexpected result - got %v, want true", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal == nil {
 		t.Fatalf("Get: unexpected result - got nil, want empty slice")
@@ -408,10 +408,7 @@ func TestImmutableForEachStopIterator(t *testing.T) {
 	var numIterated int
 	testTreap.ForEach(func(k, v []byte) bool {
 		numIterated++
-		if numIterated == numItems/2 {
+		return numIterated != numItems/2
-			return false
-		}
-		return true
 	})
 	if numIterated != numItems/2 {
 		t.Fatalf("ForEach: unexpected iterate count - got %d, want %d",

database/internal/treap/mutable_test.go

@@ -29,7 +29,7 @@ func TestMutableEmpty(t *testing.T) {
 
 	// Ensure there are no errors with requesting keys from an empty treap.
 	key := serializeUint32(0)
-	if gotVal := testTreap.Has(key); gotVal != false {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -400,8 +400,8 @@ func TestMutableDuplicatePut(t *testing.T) {
 	testTreap.Put(key, val)
 
 	// Ensure the key still exists and is the new value.
-	if gotVal := testTreap.Has(key); gotVal != true {
+	if gotVal := testTreap.Has(key); !gotVal {
-		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
+		t.Fatalf("Has: unexpected result - got %v, want true", gotVal)
 	}
 	if gotVal := testTreap.Get(key); !bytes.Equal(gotVal, val) {
 		t.Fatalf("Get: unexpected result - got %x, want %x", gotVal, val)
@@ -427,8 +427,8 @@ func TestMutableNilValue(t *testing.T) {
 	testTreap.Put(key, nil)
 
 	// Ensure the key exists and is an empty byte slice.
-	if gotVal := testTreap.Has(key); gotVal != true {
+	if gotVal := testTreap.Has(key); !gotVal {
-		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
+		t.Fatalf("Has: unexpected result - got %v, want true", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal == nil {
 		t.Fatalf("Get: unexpected result - got nil, want empty slice")
@@ -456,10 +456,7 @@ func TestMutableForEachStopIterator(t *testing.T) {
 	var numIterated int
 	testTreap.ForEach(func(k, v []byte) bool {
 		numIterated++
-		if numIterated == numItems/2 {
+		return numIterated != numItems/2
-			return false
-		}
-		return true
 	})
 	if numIterated != numItems/2 {
 		t.Fatalf("ForEach: unexpected iterate count - got %d, want %d",

mempool/mempool.go

@@ -1055,11 +1055,7 @@ func (mp *TxPool) ProcessTransaction(tx *btcutil.Tx, allowOrphan, rateLimit bool
 
 	// Potentially add the orphan transaction to the orphan pool.
 	err = mp.maybeAddOrphan(tx, tag)
-	if err != nil {
+	return nil, err
-		return nil, err
-	}
-
-	return nil, nil
 }
 
 // Count returns the number of transactions in the main pool.  It does not

peer/log.go

@@ -151,7 +151,7 @@ func sanitizeString(str string, maxLength uint) string {
 
 	// Strip any characters not in the safeChars string removed.
 	str = strings.Map(func(r rune) rune {
-		if strings.IndexRune(safeChars, r) >= 0 {
+		if strings.ContainsRune(safeChars, r) {
 			return r
 		}
 		return -1

peer/peer.go

@@ -1073,7 +1073,7 @@ func (p *Peer) handlePongMsg(msg *wire.MsgPong) {
 	if p.ProtocolVersion() > wire.BIP0031Version {
 		p.statsMtx.Lock()
 		if p.lastPingNonce != 0 && msg.Nonce == p.lastPingNonce {
-			p.lastPingMicros = time.Now().Sub(p.lastPingTime).Nanoseconds()
+			p.lastPingMicros = time.Since(p.lastPingTime).Nanoseconds()
 			p.lastPingMicros /= 1000 // convert to usec.
 			p.lastPingNonce = 0
 		}
@@ -1322,7 +1322,7 @@ out:
 
 				// Extend active deadlines by the time it took
 				// to execute the callback.
-				duration := time.Now().Sub(handlersStartTime)
+				duration := time.Since(handlersStartTime)
 				deadlineOffset += duration
 				handlerActive = false
 

rpcserver.go

@@ -2232,7 +2232,7 @@ func handleGetPeerInfo(s *rpcServer, cmd interface{}, closeChan <-chan struct{})
 			SyncNode:       p == syncPeer,
 		}
 		if p.LastPingNonce() != 0 {
-			wait := float64(time.Now().Sub(statsSnap.LastPingTime).Nanoseconds())
+			wait := float64(time.Since(statsSnap.LastPingTime).Nanoseconds())
 			// We actually want microseconds.
 			info.PingWait = wait / 1000
 		}
@@ -3740,11 +3740,7 @@ func (s *rpcServer) writeHTTPResponseHeaders(req *http.Request, headers http.Hea
 	}
 
 	_, err = io.WriteString(w, "\r\n")
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // Stop is used by server.go to stop the rpc listener.
@@ -3945,10 +3941,9 @@ func (s *rpcServer) jsonRPCRead(w http.ResponseWriter, r *http.Request, isAdmin
 	body, err := ioutil.ReadAll(r.Body)
 	r.Body.Close()
 	if err != nil {
-		errMsg := fmt.Sprintf("error reading JSON message: %v", err)
 		errCode := http.StatusBadRequest
-		http.Error(w, strconv.FormatInt(int64(errCode), 10)+" "+errMsg,
+		http.Error(w, fmt.Sprintf("%d error reading JSON message: %v",
-			errCode)
+			errCode, err), errCode)
 		return
 	}
 
@@ -3963,16 +3958,14 @@ func (s *rpcServer) jsonRPCRead(w http.ResponseWriter, r *http.Request, isAdmin
 		errMsg := "webserver doesn't support hijacking"
 		rpcsLog.Warnf(errMsg)
 		errCode := http.StatusInternalServerError
-		http.Error(w, strconv.FormatInt(int64(errCode), 10)+" "+errMsg,
+		http.Error(w, strconv.Itoa(errCode)+" "+errMsg, errCode)
-			errCode)
 		return
 	}
 	conn, buf, err := hj.Hijack()
 	if err != nil {
 		rpcsLog.Warnf("Failed to hijack HTTP connection: %v", err)
 		errCode := http.StatusInternalServerError
-		http.Error(w, strconv.FormatInt(int64(errCode), 10)+" "+
+		http.Error(w, strconv.Itoa(errCode)+" "+err.Error(), errCode)
-			err.Error(), errCode)
 		return
 	}
 	defer conn.Close()

rpctest/rpc_harness.go

@@ -240,16 +240,13 @@ func (h *Harness) SetUp(createTestChain bool, numMatureOutputs uint32) error {
 		return err
 	}
 	ticker := time.NewTicker(time.Millisecond * 100)
-out:
+	for range ticker.C {
-	for {
+		walletHeight := h.wallet.SyncedHeight()
-		select {
+		if walletHeight == height {
-		case <-ticker.C:
+			break
-			walletHeight := h.wallet.SyncedHeight()
-			if walletHeight == height {
-				break out
-			}
 		}
 	}
+	ticker.Stop()
 
 	return nil
 }

server.go

@@ -2424,7 +2424,7 @@ func newServer(listenAddrs []string, db database.DB, chainParams *chaincfg.Param
 
 				// only allow recent nodes (10mins) after we failed 30
 				// times
-				if tries < 30 && time.Now().Sub(addr.LastAttempt()) < 10*time.Minute {
+				if tries < 30 && time.Since(addr.LastAttempt()) < 10*time.Minute {
 					continue
 				}
 

service_windows.go

@@ -156,12 +156,7 @@ func installService() error {
 	// messges instead of needing to create our own message catalog.
 	eventlog.Remove(svcName)
 	eventsSupported := uint32(eventlog.Error | eventlog.Warning | eventlog.Info)
-	err = eventlog.InstallAsEventCreate(svcName, eventsSupported)
+	return eventlog.InstallAsEventCreate(svcName, eventsSupported)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // removeService attempts to uninstall the btcd service.  Typically this should
@@ -184,12 +179,7 @@ func removeService() error {
 	defer service.Close()
 
 	// Remove the service.
-	err = service.Delete()
+	return service.Delete()
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // startService attempts to start the btcd service.

txscript/engine.go

@@ -241,7 +241,7 @@ func (vm *Engine) CheckErrorCondition(finalScript bool) error {
 	if err != nil {
 		return err
 	}
-	if v == false {
+	if !v {
 		// Log interesting data.
 		log.Tracef("%v", newLogClosure(func() string {
 			dis0, _ := vm.DisasmScript(0)
@@ -337,7 +337,7 @@ func (vm *Engine) Step() (done bool, err error) {
 // for successful validation or an error if one occurred.
 func (vm *Engine) Execute() (err error) {
 	done := false
-	for done != true {
+	for !done {
 		log.Tracef("%v", newLogClosure(func() string {
 			dis, err := vm.DisasmPC()
 			if err != nil {

txscript/opcode.go

@@ -998,7 +998,7 @@ func opcodeVerify(op *parsedOpcode, vm *Engine) error {
 		return err
 	}
 
-	if verified != true {
+	if !verified {
 		return ErrStackVerifyFailed
 	}
 	return nil
@@ -1169,14 +1169,8 @@ func opcodeCheckSequenceVerify(op *parsedOpcode, vm *Engine) error {
 	// Mask off non-consensus bits before doing comparisons.
 	lockTimeMask := int64(wire.SequenceLockTimeIsSeconds |
 		wire.SequenceLockTimeMask)
-	err = verifyLockTime(txSequence&lockTimeMask,
+	return verifyLockTime(txSequence&lockTimeMask,
-		wire.SequenceLockTimeIsSeconds,
+		wire.SequenceLockTimeIsSeconds, sequence&lockTimeMask)
-		sequence&lockTimeMask)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // opcodeToAltStack removes the top item from the main data stack and pushes it

txscript/stack_test.go

@@ -116,7 +116,7 @@ func TestStack(t *testing.T) {
 					return err
 				}
 
-				if val != false {
+				if val {
 					return errors.New("unexpected value")
 				}
 				return nil
@@ -133,7 +133,7 @@ func TestStack(t *testing.T) {
 					return err
 				}
 
-				if val != true {
+				if !val {
 					return errors.New("unexpected value")
 				}
 				return nil
@@ -146,11 +146,7 @@ func TestStack(t *testing.T) {
 			nil,
 			func(s *stack) error {
 				_, err := s.PopBool()
-				if err != nil {
+				return err
-					return err
-				}
-
-				return nil
 			},
 			ErrStackUnderflow,
 			nil,
@@ -345,12 +341,7 @@ func TestStack(t *testing.T) {
 			"dup",
 			[][]byte{{1}},
 			func(s *stack) error {
-				err := s.DupN(1)
+				return s.DupN(1)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			nil,
 			[][]byte{{1}, {1}},
@@ -359,12 +350,7 @@ func TestStack(t *testing.T) {
 			"dup2",
 			[][]byte{{1}, {2}},
 			func(s *stack) error {
-				err := s.DupN(2)
+				return s.DupN(2)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			nil,
 			[][]byte{{1}, {2}, {1}, {2}},
@@ -373,12 +359,7 @@ func TestStack(t *testing.T) {
 			"dup3",
 			[][]byte{{1}, {2}, {3}},
 			func(s *stack) error {
-				err := s.DupN(3)
+				return s.DupN(3)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			nil,
 			[][]byte{{1}, {2}, {3}, {1}, {2}, {3}},
@@ -387,12 +368,7 @@ func TestStack(t *testing.T) {
 			"dup0",
 			[][]byte{{1}},
 			func(s *stack) error {
-				err := s.DupN(0)
+				return s.DupN(0)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			ErrStackInvalidArgs,
 			nil,
@@ -401,12 +377,7 @@ func TestStack(t *testing.T) {
 			"dup-1",
 			[][]byte{{1}},
 			func(s *stack) error {
-				err := s.DupN(-1)
+				return s.DupN(-1)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			ErrStackInvalidArgs,
 			nil,
@@ -415,12 +386,7 @@ func TestStack(t *testing.T) {
 			"dup too much",
 			[][]byte{{1}},
 			func(s *stack) error {
-				err := s.DupN(2)
+				return s.DupN(2)
-				if err != nil {
-					return err
-				}
-
-				return nil
 			},
 			ErrStackUnderflow,
 			nil,
@@ -456,7 +422,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != true {
+				if !val {
 					return errors.New("unexpected value")
 				}
 
@@ -474,7 +440,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != false {
+				if val {
 					return errors.New("unexpected value")
 				}
 
@@ -492,7 +458,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != true {
+				if !val {
 					return errors.New("unexpected value")
 				}
 
@@ -510,7 +476,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != false {
+				if val {
 					return errors.New("unexpected value")
 				}
 
@@ -809,7 +775,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != true {
+				if !val {
 					return errors.New("invalid result")
 				}
 				return nil
@@ -827,7 +793,7 @@ func TestStack(t *testing.T) {
 				if err != nil {
 					return err
 				}
-				if val != false {
+				if val {
 					return errors.New("invalid result")
 				}
 				return nil

upgrade.go

@@ -101,12 +101,7 @@ func upgradeDBPaths() error {
 	upgradeDBPathNet(filepath.Join(oldDbRoot, "btcd_regtest.db"), "regtest")
 
 	// Remove the old db directory.
-	err := os.RemoveAll(oldDbRoot)
+	return os.RemoveAll(oldDbRoot)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // upgradeDataPaths moves the application data from its location prior to btcd

upnp.go

@@ -104,7 +104,7 @@ func Discover() (nat NAT, err error) {
 			// return
 		}
 		answer := string(answerBytes[0:n])
-		if strings.Index(answer, "\r\n"+st) < 0 {
+		if !strings.Contains(answer, "\r\n"+st) {
 			continue
 		}
 		// HTTP header field names are case-insensitive.

wire/blockheader.go

@@ -117,13 +117,8 @@ func NewBlockHeader(prevHash *chainhash.Hash, merkleRootHash *chainhash.Hash,
 // decoding block headers stored to disk, such as in a database, as opposed to
 // decoding from the wire.
 func readBlockHeader(r io.Reader, pver uint32, bh *BlockHeader) error {
-	err := readElements(r, &bh.Version, &bh.PrevBlock, &bh.MerkleRoot,
+	return readElements(r, &bh.Version, &bh.PrevBlock, &bh.MerkleRoot,
 		(*uint32Time)(&bh.Timestamp), &bh.Bits, &bh.Nonce)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // writeBlockHeader writes a bitcoin block header to w.  See Serialize for
@@ -131,11 +126,6 @@ func readBlockHeader(r io.Reader, pver uint32, bh *BlockHeader) error {
 // opposed to encoding for the wire.
 func writeBlockHeader(w io.Writer, pver uint32, bh *BlockHeader) error {
 	sec := uint32(bh.Timestamp.Unix())
-	err := writeElements(w, bh.Version, &bh.PrevBlock, &bh.MerkleRoot,
+	return writeElements(w, bh.Version, &bh.PrevBlock, &bh.MerkleRoot,
 		sec, bh.Bits, bh.Nonce)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }

wire/common.go

@@ -378,7 +378,7 @@ func writeElement(w io.Writer, element interface{}) error {
 
 	case bool:
 		var err error
-		if e == true {
+		if e {
 			err = binarySerializer.PutUint8(w, 0x01)
 		} else {
 			err = binarySerializer.PutUint8(w, 0x00)
@@ -624,10 +624,7 @@ func WriteVarString(w io.Writer, pver uint32, str string) error {
 		return err
 	}
 	_, err = w.Write([]byte(str))
-	if err != nil {
+	return err
-		return err
-	}
-	return nil
 }
 
 // ReadVarBytes reads a variable length byte array.  A byte array is encoded
@@ -672,10 +669,7 @@ func WriteVarBytes(w io.Writer, pver uint32, bytes []byte) error {
 	}
 
 	_, err = w.Write(bytes)
-	if err != nil {
+	return err
-		return err
-	}
-	return nil
 }
 
 // randomUint64 returns a cryptographically random uint64 value.  This

wire/invvect.go

@@ -67,18 +67,10 @@ func NewInvVect(typ InvType, hash *chainhash.Hash) *InvVect {
 // readInvVect reads an encoded InvVect from r depending on the protocol
 // version.
 func readInvVect(r io.Reader, pver uint32, iv *InvVect) error {
-	err := readElements(r, &iv.Type, &iv.Hash)
+	return readElements(r, &iv.Type, &iv.Hash)
-	if err != nil {
-		return err
-	}
-	return nil
 }
 
 // writeInvVect serializes an InvVect to w depending on the protocol version.
 func writeInvVect(w io.Writer, pver uint32, iv *InvVect) error {
-	err := writeElements(w, iv.Type, &iv.Hash)
+	return writeElements(w, iv.Type, &iv.Hash)
-	if err != nil {
-		return err
-	}
-	return nil
 }

wire/message.go

@@ -261,11 +261,7 @@ func WriteMessageN(w io.Writer, msg Message, pver uint32, btcnet BitcoinNet) (in
 	// Write payload.
 	n, err = w.Write(payload)
 	totalBytes += n
-	if err != nil {
+	return totalBytes, err
-		return totalBytes, err
-	}
-
-	return totalBytes, nil
 }
 
 // WriteMessage writes a bitcoin Message to w including the necessary header

wire/msgalert.go

@@ -206,11 +206,7 @@ func (alert *Alert) Serialize(w io.Writer, pver uint32) error {
 	if err != nil {
 		return err
 	}
-	err = WriteVarString(w, pver, alert.Reserved)
+	return WriteVarString(w, pver, alert.Reserved)
-	if err != nil {
-		return err
-	}
-	return nil
 }
 
 // Deserialize decodes from r into the receiver using the alert protocol
@@ -279,10 +275,7 @@ func (alert *Alert) Deserialize(r io.Reader, pver uint32) error {
 		return err
 	}
 	alert.Reserved, err = ReadVarString(r, pver)
-	if err != nil {
+	return err
-		return err
-	}
-	return nil
 }
 
 // NewAlert returns an new Alert with values provided.
@@ -356,11 +349,7 @@ func (msg *MsgAlert) BtcDecode(r io.Reader, pver uint32) error {
 
 	msg.Signature, err = ReadVarBytes(r, pver, MaxMessagePayload,
 		"alert signature")
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -390,11 +379,7 @@ func (msg *MsgAlert) BtcEncode(w io.Writer, pver uint32) error {
 	if err != nil {
 		return err
 	}
-	err = WriteVarBytes(w, pver, msg.Signature)
+	return WriteVarBytes(w, pver, msg.Signature)
-	if err != nil {
-		return err
-	}
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgfeefilter.go

@@ -28,12 +28,7 @@ func (msg *MsgFeeFilter) BtcDecode(r io.Reader, pver uint32) error {
 		return messageError("MsgFeeFilter.BtcDecode", str)
 	}
 
-	err := readElement(r, &msg.MinFee)
+	return readElement(r, &msg.MinFee)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -45,12 +40,7 @@ func (msg *MsgFeeFilter) BtcEncode(w io.Writer, pver uint32) error {
 		return messageError("MsgFeeFilter.BtcEncode", str)
 	}
 
-	err := writeElement(w, msg.MinFee)
+	return writeElement(w, msg.MinFee)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgfilteradd.go

@@ -37,11 +37,7 @@ func (msg *MsgFilterAdd) BtcDecode(r io.Reader, pver uint32) error {
 	var err error
 	msg.Data, err = ReadVarBytes(r, pver, MaxFilterAddDataSize,
 		"filteradd data")
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -60,12 +56,7 @@ func (msg *MsgFilterAdd) BtcEncode(w io.Writer, pver uint32) error {
 		return messageError("MsgFilterAdd.BtcEncode", str)
 	}
 
-	err := WriteVarBytes(w, pver, msg.Data)
+	return WriteVarBytes(w, pver, msg.Data)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgfilterload.go

@@ -106,12 +106,7 @@ func (msg *MsgFilterLoad) BtcEncode(w io.Writer, pver uint32) error {
 		return err
 	}
 
-	err = writeElements(w, msg.HashFuncs, msg.Tweak, msg.Flags)
+	return writeElements(w, msg.HashFuncs, msg.Tweak, msg.Flags)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msggetblocks.go

@@ -80,12 +80,7 @@ func (msg *MsgGetBlocks) BtcDecode(r io.Reader, pver uint32) error {
 		msg.AddBlockLocatorHash(hash)
 	}
 
-	err = readElement(r, &msg.HashStop)
+	return readElement(r, &msg.HashStop)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -115,12 +110,7 @@ func (msg *MsgGetBlocks) BtcEncode(w io.Writer, pver uint32) error {
 		}
 	}
 
-	err = writeElement(w, &msg.HashStop)
+	return writeElement(w, &msg.HashStop)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msggetheaders.go

@@ -77,12 +77,7 @@ func (msg *MsgGetHeaders) BtcDecode(r io.Reader, pver uint32) error {
 		msg.AddBlockLocatorHash(hash)
 	}
 
-	err = readElement(r, &msg.HashStop)
+	return readElement(r, &msg.HashStop)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -113,12 +108,7 @@ func (msg *MsgGetHeaders) BtcEncode(w io.Writer, pver uint32) error {
 		}
 	}
 
-	err = writeElement(w, &msg.HashStop)
+	return writeElement(w, &msg.HashStop)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgmerkleblock.go

@@ -85,11 +85,7 @@ func (msg *MsgMerkleBlock) BtcDecode(r io.Reader, pver uint32) error {
 
 	msg.Flags, err = ReadVarBytes(r, pver, maxFlagsPerMerkleBlock,
 		"merkle block flags size")
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -136,12 +132,7 @@ func (msg *MsgMerkleBlock) BtcEncode(w io.Writer, pver uint32) error {
 		}
 	}
 
-	err = WriteVarBytes(w, pver, msg.Flags)
+	return WriteVarBytes(w, pver, msg.Flags)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgpong.go

@@ -31,12 +31,7 @@ func (msg *MsgPong) BtcDecode(r io.Reader, pver uint32) error {
 		return messageError("MsgPong.BtcDecode", str)
 	}
 
-	err := readElement(r, &msg.Nonce)
+	return readElement(r, &msg.Nonce)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
@@ -50,12 +45,7 @@ func (msg *MsgPong) BtcEncode(w io.Writer, pver uint32) error {
 		return messageError("MsgPong.BtcEncode", str)
 	}
 
-	err := writeElement(w, msg.Nonce)
+	return writeElement(w, msg.Nonce)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Command returns the protocol command string for the message.  This is part

wire/msgtx.go

@@ -537,12 +537,7 @@ func (msg *MsgTx) BtcEncode(w io.Writer, pver uint32) error {
 		}
 	}
 
-	err = binarySerializer.PutUint32(w, littleEndian, msg.LockTime)
+	return binarySerializer.PutUint32(w, littleEndian, msg.LockTime)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // Serialize encodes the transaction to w using a format that suitable for
@@ -652,11 +647,7 @@ func readOutPoint(r io.Reader, pver uint32, version int32, op *OutPoint) error {
 	}
 
 	op.Index, err = binarySerializer.Uint32(r, littleEndian)
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // writeOutPoint encodes op to the bitcoin protocol encoding for an OutPoint
@@ -667,11 +658,7 @@ func writeOutPoint(w io.Writer, pver uint32, version int32, op *OutPoint) error
 		return err
 	}
 
-	err = binarySerializer.PutUint32(w, littleEndian, op.Index)
+	return binarySerializer.PutUint32(w, littleEndian, op.Index)
-	if err != nil {
-		return err
-	}
-	return nil
 }
 
 // readScript reads a variable length byte array that represents a transaction
@@ -719,12 +706,7 @@ func readTxIn(r io.Reader, pver uint32, version int32, ti *TxIn) error {
 		return err
 	}
 
-	err = readElement(r, &ti.Sequence)
+	return readElement(r, &ti.Sequence)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // writeTxIn encodes ti to the bitcoin protocol encoding for a transaction
@@ -740,12 +722,7 @@ func writeTxIn(w io.Writer, pver uint32, version int32, ti *TxIn) error {
 		return err
 	}
 
-	err = binarySerializer.PutUint32(w, littleEndian, ti.Sequence)
+	return binarySerializer.PutUint32(w, littleEndian, ti.Sequence)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // readTxOut reads the next sequence of bytes from r as a transaction output
@@ -758,11 +735,7 @@ func readTxOut(r io.Reader, pver uint32, version int32, to *TxOut) error {
 
 	to.PkScript, err = readScript(r, pver, MaxMessagePayload,
 		"transaction output public key script")
-	if err != nil {
+	return err
-		return err
-	}
-
-	return nil
 }
 
 // writeTxOut encodes to into the bitcoin protocol encoding for a transaction
@@ -773,9 +746,5 @@ func writeTxOut(w io.Writer, pver uint32, version int32, to *TxOut) error {
 		return err
 	}
 
-	err = WriteVarBytes(w, pver, to.PkScript)
+	return WriteVarBytes(w, pver, to.PkScript)
-	if err != nil {
-		return err
-	}
-	return nil
 }

wire/msgversion_test.go

@@ -63,7 +63,7 @@ func TestVersion(t *testing.T) {
 		t.Errorf("NewMsgVersion: wrong last block - got %v, want %v",
 			msg.LastBlock, lastBlock)
 	}
-	if msg.DisableRelayTx != false {
+	if msg.DisableRelayTx {
 		t.Errorf("NewMsgVersion: disable relay tx is not false by "+
 			"default - got %v, want %v", msg.DisableRelayTx, false)
 	}

wire/netaddress.go

@@ -53,10 +53,7 @@ type NetAddress struct {
 
 // HasService returns whether the specified service is supported by the address.
 func (na *NetAddress) HasService(service ServiceFlag) bool {
-	if na.Services&service == service {
+	return na.Services&service == service
-		return true
-	}
-	return false
 }
 
 // AddService adds service as a supported service by the peer generating the
@@ -158,10 +155,5 @@ func writeNetAddress(w io.Writer, pver uint32, na *NetAddress, ts bool) error {
 	}
 
 	// Sigh.  Bitcoin protocol mixes little and big endian.
-	err = binary.Write(w, bigEndian, na.Port)
+	return binary.Write(w, bigEndian, na.Port)
-	if err != nil {
-		return err
-	}
-
-	return nil
 }