multi: Wrap errors for better errors.Is/As support.

This updates all remaining cases of unwrapped errors in fmt.Errorf calls
to wrap the underlying errors with the %w format verb to ensure they
work nicely with errors.Is and errors.As.

addrmgr/addrmanager.go

@@ -1,5 +1,5 @@
 // Copyright (c) 2013-2014 The btcsuite developers
-// Copyright (c) 2015-2021 The Decred developers
+// Copyright (c) 2015-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -531,15 +531,15 @@ func (a *AddrManager) deserializePeers(filePath string) error {
 	}
 	r, err := os.Open(filePath)
 	if err != nil {
-		return fmt.Errorf("%s error opening file: %v", filePath, err)
+		return fmt.Errorf("%s error opening file: %w", filePath, err)
 	}
 	defer r.Close()
 
 	var sam serializedAddrManager
 	dec := json.NewDecoder(r)
 	err = dec.Decode(&sam)
 	if err != nil {
-		return fmt.Errorf("error reading %s: %v", filePath, err)
+		return fmt.Errorf("error reading %s: %w", filePath, err)
 	}
 
 	if sam.Version != serialisationVersion {
@@ -551,13 +551,13 @@ func (a *AddrManager) deserializePeers(filePath string) error {
 	for _, v := range sam.Addresses {
 		netAddr, err := a.newAddressFromString(v.Addr)
 		if err != nil {
-			return fmt.Errorf("failed to deserialize netaddress "+
-				"%s: %v", v.Addr, err)
+			return fmt.Errorf("failed to deserialize netaddress %s: %w", v.Addr,
+				err)
 		}
 		srcAddr, err := a.newAddressFromString(v.Src)
 		if err != nil {
-			return fmt.Errorf("failed to deserialize netaddress "+
-				"%s: %v", v.Src, err)
+			return fmt.Errorf("failed to deserialize netaddress %s: %w", v.Src,
+				err)
 		}
 
 		ka := &KnownAddress{

certgen/certgen.go

@@ -1,5 +1,5 @@
 // Copyright (c) 2013-2015 The btcsuite developers
-// Copyright (c) 2015-2017 The Decred developers
+// Copyright (c) 2015-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -45,7 +45,7 @@ func NewTLSCertPair(curve elliptic.Curve, organization string, validUntil time.T
 	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to generate serial number: %s", err)
+		return nil, nil, fmt.Errorf("failed to generate serial number: %w", err)
 	}
 
 	host, err := os.Hostname()
@@ -120,24 +120,24 @@ func NewTLSCertPair(curve elliptic.Curve, organization string, validUntil time.T
 	derBytes, err := x509.CreateCertificate(rand.Reader, &template,
 		&template, &priv.PublicKey, priv)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to create certificate: %v", err)
+		return nil, nil, fmt.Errorf("failed to create certificate: %w", err)
 	}
 
 	certBuf := &bytes.Buffer{}
 	err = pem.Encode(certBuf, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to encode certificate: %v", err)
+		return nil, nil, fmt.Errorf("failed to encode certificate: %w", err)
 	}
 
 	keybytes, err := x509.MarshalECPrivateKey(priv)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to marshal private key: %v", err)
+		return nil, nil, fmt.Errorf("failed to marshal private key: %w", err)
 	}
 
 	keyBuf := &bytes.Buffer{}
 	err = pem.Encode(keyBuf, &pem.Block{Type: "EC PRIVATE KEY", Bytes: keybytes})
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to encode private key: %v", err)
+		return nil, nil, fmt.Errorf("failed to encode private key: %w", err)
 	}
 
 	return certBuf.Bytes(), keyBuf.Bytes(), nil

certgen/certgen_ed25519.go

@@ -1,5 +1,5 @@
 // Copyright (c) 2013-2015 The btcsuite developers
-// Copyright (c) 2015-2019 The Decred developers
+// Copyright (c) 2015-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -48,7 +48,7 @@ func NewEd25519TLSCertPair(organization string, validUntil time.Time, extraHosts
 	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to generate serial number: %s", err)
+		return nil, nil, fmt.Errorf("failed to generate serial number: %w", err)
 	}
 
 	host, err := os.Hostname()
@@ -123,24 +123,24 @@ func NewEd25519TLSCertPair(organization string, validUntil time.Time, extraHosts
 	derBytes, err := x509.CreateCertificate(rand.Reader, &template,
 		&template, priv.Public(), priv)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to create certificate: %v", err)
+		return nil, nil, fmt.Errorf("failed to create certificate: %w", err)
 	}
 
 	certBuf := &bytes.Buffer{}
 	err = pem.Encode(certBuf, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to encode certificate: %v", err)
+		return nil, nil, fmt.Errorf("failed to encode certificate: %w", err)
 	}
 
 	keybytes, err := x509.MarshalPKCS8PrivateKey(priv)
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to marshal private key: %v", err)
+		return nil, nil, fmt.Errorf("failed to marshal private key: %w", err)
 	}
 
 	keyBuf := &bytes.Buffer{}
 	err = pem.Encode(keyBuf, &pem.Block{Type: "PRIVATE KEY", Bytes: keybytes})
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to encode private key: %v", err)
+		return nil, nil, fmt.Errorf("failed to encode private key: %w", err)
 	}
 
 	return certBuf.Bytes(), keyBuf.Bytes(), nil

cmd/gencerts/gencerts.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 The Decred developers
+// Copyright (c) 2020-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -206,7 +206,7 @@ func randomX509SerialNumber() (*big.Int, error) {
 	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate serial number: %s", err)
+		return nil, fmt.Errorf("failed to generate serial number: %w", err)
 	}
 	return serialNumber, nil
 }
@@ -277,7 +277,7 @@ func generateAuthority(pub, priv interface{}, hosts []string, org string, years
 	buf := new(bytes.Buffer)
 	err = pem.Encode(buf, &pem.Block{Type: "CERTIFICATE", Bytes: cert})
 	if err != nil {
-		return nil, fmt.Errorf("failed to encode certificate: %v", err)
+		return nil, fmt.Errorf("failed to encode certificate: %w", err)
 	}
 	pemBlock := buf.Bytes()
 
@@ -317,7 +317,7 @@ func createIssuedCert(pub, caPriv interface{}, ca *x509.Certificate,
 	buf := new(bytes.Buffer)
 	err = pem.Encode(buf, &pem.Block{Type: "CERTIFICATE", Bytes: cert})
 	if err != nil {
-		return nil, fmt.Errorf("failed to encode certificate: %v", err)
+		return nil, fmt.Errorf("failed to encode certificate: %w", err)
 	}
 	pemBlock := buf.Bytes()
 
@@ -336,12 +336,12 @@ func createIssuedCert(pub, caPriv interface{}, ca *x509.Certificate,
 func marshalPrivateKey(key interface{}) ([]byte, error) {
 	der, err := x509.MarshalPKCS8PrivateKey(key)
 	if err != nil {
-		return nil, fmt.Errorf("failed to marshal private key: %v", err)
+		return nil, fmt.Errorf("failed to marshal private key: %w", err)
 	}
 	buf := new(bytes.Buffer)
 	err = pem.Encode(buf, &pem.Block{Type: "PRIVATE KEY", Bytes: der})
 	if err != nil {
-		return nil, fmt.Errorf("failed to encode private key: %v", err)
+		return nil, fmt.Errorf("failed to encode private key: %w", err)
 	}
 	return buf.Bytes(), nil
 }

dcrutil/util.go

@@ -1,5 +1,5 @@
 // Copyright (c) 2013, 2014 The btcsuite developers
-// Copyright (c) 2015-2021 The Decred developers
+// Copyright (c) 2015-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -62,7 +62,7 @@ func VerifyMessage(address string, signature string, message string, params Addr
 	// Decode base64 signature.
 	sig, err := base64.StdEncoding.DecodeString(signature)
 	if err != nil {
-		return fmt.Errorf("malformed base64 encoding: %v", err)
+		return fmt.Errorf("malformed base64 encoding: %w", err)
 	}
 
 	// Validate the signature - this just shows that it was valid for any pubkey

internal/blockchain/utxobackend_test.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021-2022 The Decred developers
+// Copyright (c) 2021-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -73,22 +73,22 @@ func TestConvertLdbErr(t *testing.T) {
 		gotErr := convertLdbErr(test.ldbErr, test.desc)
 
 		// Validate the error kind.
-		if gotErr.Err != test.want {
+		if !errors.Is(gotErr.Err, test.want) {
 			t.Errorf("%q: mismatched error kind:\nwant: %v\n got: %v\n",
 				test.name, test.want, gotErr.Err)
 			continue
 		}
 
-		wantDesc := fmt.Sprintf("%s: %v", test.desc, test.ldbErr)
 		// Validate the error description.
+		wantDesc := fmt.Sprintf("%s: %v", test.desc, test.ldbErr)
 		if gotErr.Description != wantDesc {
 			t.Errorf("%q: mismatched error description:\nwant: %v\n got: %v\n",
 				test.name, wantDesc, gotErr.Description)
 			continue
 		}
 
 		// Validate the raw error.
-		if gotErr.RawErr != test.ldbErr {
+		if !errors.Is(gotErr.RawErr, test.ldbErr) {
 			t.Errorf("%q: mismatched raw error:\nwant: %v\n got: %v\n",
 				test.name, test.ldbErr, gotErr.RawErr)
 			continue

internal/fees/estimator.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2022 The Decred developers
+// Copyright (c) 2018-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -228,13 +228,13 @@ func NewEstimator(cfg *EstimatorConfig) (*Estimator, error) {
 	if cfg.DatabaseFile != "" {
 		db, err := leveldb.OpenFile(cfg.DatabaseFile, nil)
 		if err != nil {
-			return nil, fmt.Errorf("error opening estimator database: %v", err)
+			return nil, fmt.Errorf("error opening estimator database: %w", err)
 		}
 		res.db = db
 
 		err = res.loadFromDatabase(cfg.ReplaceBucketsOnLoad)
 		if err != nil {
-			return nil, fmt.Errorf("error loading estimator data from db: %v",
+			return nil, fmt.Errorf("error loading estimator data from db: %w",
 				err)
 		}
 	}
@@ -307,7 +307,7 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 
 	version, err := stats.db.Get(dbKeyVersion, nil)
 	if err != nil && !errors.Is(err, leveldb.ErrNotFound) {
-		return fmt.Errorf("error reading version from db: %v", err)
+		return fmt.Errorf("error reading version from db: %w", err)
 	}
 	if len(version) < 1 {
 		// No data in the file. Fill with the current config.
@@ -326,19 +326,19 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 
 		err := binary.Write(b, dbByteOrder, stats.bucketFeeBounds)
 		if err != nil {
-			return fmt.Errorf("error writing bucket fees to db: %v", err)
+			return fmt.Errorf("error writing bucket fees to db: %w", err)
 		}
 		batch.Put(dbKeyBucketFees, b.Bytes())
 
 		err = stats.db.Write(batch, nil)
 		if err != nil {
-			return fmt.Errorf("error writing initial estimator db file: %v",
+			return fmt.Errorf("error writing initial estimator db file: %w",
 				err)
 		}
 
 		err = stats.updateDatabase()
 		if err != nil {
-			return fmt.Errorf("error adding initial estimator data to db: %v",
+			return fmt.Errorf("error adding initial estimator data to db: %w",
 				err)
 		}
 
@@ -354,7 +354,7 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 	maxConfirmsBytes, err := stats.db.Get(dbKeyMaxConfirms, nil)
 	if err != nil {
 		return fmt.Errorf("error reading max confirmation range from db file: "+
-			"%v", err)
+			"%w", err)
 	}
 	if len(maxConfirmsBytes) != 4 {
 		return errors.New("wrong number of bytes in stored maxConfirms")
@@ -367,7 +367,7 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 
 	feesBytes, err := stats.db.Get(dbKeyBucketFees, nil)
 	if err != nil {
-		return fmt.Errorf("error reading fee bounds from db file: %v", err)
+		return fmt.Errorf("error reading fee bounds from db file: %w", err)
 	}
 	if feesBytes == nil {
 		return errors.New("fee bounds not found in database file")
@@ -381,7 +381,7 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 	err = binary.Read(bytes.NewReader(feesBytes), dbByteOrder,
 		&fileBucketFees)
 	if err != nil {
-		return fmt.Errorf("error decoding file bucket fees: %v", err)
+		return fmt.Errorf("error decoding file bucket fees: %w", err)
 	}
 
 	if !replaceBuckets {
@@ -450,7 +450,7 @@ func (stats *Estimator) loadFromDatabase(replaceBuckets bool) error {
 	}
 	err = iter.Error()
 	if err != nil {
-		return fmt.Errorf("error on bucket iterator: %v", err)
+		return fmt.Errorf("error on bucket iterator: %w", err)
 	}
 
 	stats.bucketFeeBounds = fileBucketFees
@@ -502,8 +502,7 @@ func (stats *Estimator) updateDatabase() error {
 
 	err := stats.db.Write(batch, nil)
 	if err != nil {
-		return fmt.Errorf("error writing update to estimator db file: %v",
-			err)
+		return fmt.Errorf("error writing update to estimator db file: %w", err)
 	}
 
 	return nil

internal/staging/banmanager/banmanager.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 The Decred developers
+// Copyright (c) 2021-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -119,7 +119,7 @@ func (bm *BanManager) AddPeer(p *peer.Peer) error {
 	host, _, err := net.SplitHostPort(p.Addr())
 	if err != nil {
 		p.Disconnect()
-		return fmt.Errorf("cannot split hostport %v", err)
+		return fmt.Errorf("cannot split hostport %w", err)
 	}
 
 	bm.mtx.Lock()

rpcclient/infrastructure.go

@@ -759,7 +759,7 @@ func (c *Client) handleSendPostMessage(details *sendPostDetails) {
 	respBytes, err := io.ReadAll(httpResponse.Body)
 	httpResponse.Body.Close()
 	if err != nil {
-		err = fmt.Errorf("error reading json reply: %v", err)
+		err = fmt.Errorf("error reading json reply: %w", err)
 		jReq.responseChan <- &response{err: err}
 		return
 	}