Fix panic in getaddressesbyaccount.

rpc/legacyrpc/methods.go

@@ -319,7 +319,7 @@ func jsonError(err error) *dcrjson.RPCError {
 	}
 }
 
-// accountAddressIndex returns the current address index for the passed
+// accountAddressIndex returns the next address index for the passed
 // account and branch.
 func accountAddressIndex(icmd interface{}, w *wallet.Wallet) (interface{}, error) {
 	cmd := icmd.(*dcrjson.AccountAddressIndexCmd)
@@ -328,7 +328,7 @@ func accountAddressIndex(icmd interface{}, w *wallet.Wallet) (interface{}, error
 		return nil, err
 	}
 
-	extChild, intChild, err := w.BIP0044BranchIndexes(account)
+	extChild, intChild, err := w.BIP0044BranchNextIndexes(account)
 	if err != nil {
 		return nil, err
 	}
@@ -365,8 +365,10 @@ func accountFetchAddresses(icmd interface{}, w *wallet.Wallet) (interface{}, err
 			cmd.End)
 	}
 
-	addrs, err := w.AccountBranchAddressRange(uint32(cmd.Start),
-		uint32(cmd.End), account, branch)
+	// AccountBranchAddressRange uses the range [start, end) but the RPC for
+	// some reason uses (start, end], so add to each index.
+	addrs, err := w.AccountBranchAddressRange(account, branch, uint32(cmd.Start)+1,
+		uint32(cmd.End)+1)
 	if err != nil {
 		return nil, err
 	}
@@ -634,8 +636,8 @@ func getAddressesByAccount(icmd interface{}, w *wallet.Wallet) (interface{}, err
 		return nil, err
 	}
 
-	// Find the current synced-to indexes from the address pool.
-	endExt, endInt, err := w.BIP0044BranchIndexes(account)
+	// Find the next child address indexes for the account.
+	endExt, endInt, err := w.BIP0044BranchNextIndexes(account)
 	if err != nil {
 		return nil, err
 	}
@@ -647,16 +649,14 @@ func getAddressesByAccount(icmd interface{}, w *wallet.Wallet) (interface{}, err
 
 	// Derive the addresses.
 	addrsStr := make([]string, endInt+endExt)
-	addrsExt, err := w.AccountBranchAddressRange(0, endExt,
-		account, udb.ExternalBranch)
+	addrsExt, err := w.AccountBranchAddressRange(account, udb.ExternalBranch, 0, endExt)
 	if err != nil {
 		return nil, err
 	}
 	for i := range addrsExt {
 		addrsStr[i] = addrsExt[i].EncodeAddress()
 	}
-	addrsInt, err := w.AccountBranchAddressRange(0, endInt,
-		account, udb.InternalBranch)
+	addrsInt, err := w.AccountBranchAddressRange(account, udb.InternalBranch, 0, endInt)
 	if err != nil {
 		return nil, err
 	}

wallet/addresses.go

@@ -262,9 +262,9 @@ func (w *Wallet) NewInternalAddress(account uint32) (dcrutil.Address, error) {
 	return w.nextAddress(account, udb.InternalBranch)
 }
 
-// BIP0044BranchIndexes returns the current external and internal branch child
+// BIP0044BranchNextIndexes returns the next external and internal branch child
 // indexes of an account.
-func (w *Wallet) BIP0044BranchIndexes(account uint32) (extChild, intChild uint32, err error) {
+func (w *Wallet) BIP0044BranchNextIndexes(account uint32) (extChild, intChild uint32, err error) {
 	defer w.addressBuffersMu.Unlock()
 	w.addressBuffersMu.Lock()
 
@@ -273,8 +273,8 @@ func (w *Wallet) BIP0044BranchIndexes(account uint32) (extChild, intChild uint32
 		const str = "account not found"
 		return 0, 0, apperrors.E{ErrorCode: apperrors.ErrAccountNotFound, Description: str, Err: nil}
 	}
-	extChild = acctData.albExternal.lastUsed + acctData.albExternal.cursor
-	intChild = acctData.albInternal.lastUsed + acctData.albInternal.cursor
+	extChild = acctData.albExternal.lastUsed + 1 + acctData.albExternal.cursor
+	intChild = acctData.albInternal.lastUsed + 1 + acctData.albInternal.cursor
 	return extChild, intChild, nil
 }
 
@@ -341,6 +341,36 @@ func (w *Wallet) ExtendWatchedAddresses(account, branch, child uint32) error {
 	return nil
 }
 
+// AccountBranchAddressRange returns all addresses in the range [start, end)
+// belonging to the BIP0044 account and address branch.
+func (w *Wallet) AccountBranchAddressRange(account, branch, start, end uint32) ([]dcrutil.Address, error) {
+	if end < start {
+		const str = "end index must not be less than start index"
+		return nil, apperrors.E{ErrorCode: apperrors.ErrInput, Description: str, Err: nil}
+	}
+
+	defer w.addressBuffersMu.Unlock()
+	w.addressBuffersMu.Lock()
+
+	acctBufs, ok := w.addressBuffers[account]
+	if !ok {
+		const str = "account not found"
+		return nil, apperrors.E{ErrorCode: apperrors.ErrAccountNotFound, Description: str, Err: nil}
+	}
+
+	var buf *addressBuffer
+	switch branch {
+	case udb.ExternalBranch:
+		buf = &acctBufs.albExternal
+	case udb.InternalBranch:
+		buf = &acctBufs.albInternal
+	default:
+		const str = "unknown branch"
+		return nil, apperrors.E{ErrorCode: apperrors.ErrBranch, Description: str, Err: nil}
+	}
+	return deriveChildAddresses(buf.branchXpub, start, end-start, w.chainParams)
+}
+
 func (w *Wallet) changeSource(account uint32) txauthor.ChangeSource {
 	return func() ([]byte, uint16, error) {
 		changeAddress, err := w.changeAddress(account)

wallet/wallet.go

@@ -1611,32 +1611,6 @@ func (w *Wallet) CurrentAddress(account uint32) (dcrutil.Address, error) {
 	return child.Address(w.chainParams)
 }
 
-// AccountBranchAddressRange returns all addresses in the left-open,
-// right-closed range (start, end] belonging to the BIP0044 account and address
-// branch.
-func (w *Wallet) AccountBranchAddressRange(start, end uint32, account uint32, branch uint32) ([]dcrutil.Address, error) {
-	defer w.addressBuffersMu.Unlock()
-	w.addressBuffersMu.Lock()
-
-	acctBufs, ok := w.addressBuffers[account]
-	if !ok {
-		const str = "account not found"
-		return nil, apperrors.E{ErrorCode: apperrors.ErrAccountNotFound, Description: str, Err: nil}
-	}
-
-	var buf *addressBuffer
-	switch branch {
-	case udb.ExternalBranch:
-		buf = &acctBufs.albExternal
-	case udb.InternalBranch:
-		buf = &acctBufs.albInternal
-	default:
-		const str = "unknown branch"
-		return nil, apperrors.E{ErrorCode: apperrors.ErrBranch, Description: str, Err: nil}
-	}
-	return deriveChildAddresses(buf.branchXpub, start+1, end-start+1, w.chainParams)
-}
-
 // PubKeyForAddress looks up the associated public key for a P2PKH address.
 func (w *Wallet) PubKeyForAddress(a dcrutil.Address) (chainec.PublicKey, error) {
 	var pubKey chainec.PublicKey