birthday: Set correctly for existing wallets.

Add a new method that can be used to correctly set the birthday for
existing wallets that have already completed initial sync.

wallet/rescan.go

@@ -497,9 +497,13 @@ func (w *Wallet) rescanPoint(dbtx walletdb.ReadTx) (*chainhash.Hash, error) {
 	return &rescanPoint, nil
 }
 
-// SetBirthState sets the birthday state in the database.
+// SetBirthState sets the birthday state in the database. This should be called
+// before initial sync has happened.
 func (w *Wallet) SetBirthState(ctx context.Context, bs *udb.BirthdayState) error {
 	const op errors.Op = "wallet.SetBirthState"
+	if bs == nil {
+		return errors.E(op, errors.Invalid, "nil birthday state")
+	}
 	err := walletdb.Update(ctx, w.db, func(dbtx walletdb.ReadWriteTx) error {
 		return udb.SetBirthState(dbtx, bs)
 	})
@@ -509,7 +513,8 @@ func (w *Wallet) SetBirthState(ctx context.Context, bs *udb.BirthdayState) error
 	return nil
 }
 
-// BirthState returns the birthday state.
+// BirthState returns the birthday state. Will return a nil state if none has
+// been set.
 func (w *Wallet) BirthState(ctx context.Context) (bs *udb.BirthdayState, err error) {
 	const op errors.Op = "wallet.BirthState"
 	err = walletdb.View(ctx, w.db, func(dbtx walletdb.ReadTx) error {
@@ -521,3 +526,42 @@ func (w *Wallet) BirthState(ctx context.Context) (bs *udb.BirthdayState, err err
 	}
 	return bs, nil
 }
+
+// SetBirthStateAndScan sets the wallet birthstate. This version should be used
+// to change the birth state after initial sync has happened. It will find an
+// adequate block from time or height.
+func (w *Wallet) SetBirthStateAndScan(ctx context.Context, bs *udb.BirthdayState) error {
+	if bs == nil {
+		return errors.New("nil birthday state")
+	}
+	if !(bs.SetFromTime || bs.SetFromHeight) {
+		return errors.New("nothing to set")
+	}
+	tipHash, _ := w.MainChainTip(ctx)
+	syncedHeader, err := w.BlockHeader(ctx, &tipHash)
+	if err != nil {
+		return err
+	}
+	h := syncedHeader
+	for {
+		if (bs.SetFromTime && (h.Height == 0 || h.Timestamp.After(bs.Time))) ||
+			bs.SetFromHeight && h.Height <= bs.Height {
+			bh := h.BlockHash()
+			height := h.Height
+			bs.Hash = bh
+			bs.Height = height
+			bs.SetFromTime = false
+			bs.SetFromHeight = false
+			if err := w.SetBirthState(ctx, bs); err != nil {
+				return err
+			}
+			log.Infof("Set wallet birthday to block %d (%v).", height, bh)
+			break
+		}
+		h, err = w.BlockHeader(ctx, &h.PrevBlock)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

wallet/udb/txmined.go

@@ -331,7 +331,8 @@ type BirthdayState struct {
 	SetFromHeight, SetFromTime bool
 }
 
-// SetBirthState sets the birthday state in the database.
+// SetBirthState sets the birthday state in the database. *BirthdayState must
+// not be nil.
 //
 // [0:1] Options (1 byte)
 // [1:33]  Birthblock block header hash (32 bytes)
@@ -361,7 +362,8 @@ func SetBirthState(dbtx walletdb.ReadWriteTx, bs *BirthdayState) error {
 	return ns.Put(rootBirthState, v)
 }
 
-// BirthState returns the current birthday state.
+// BirthState returns the current birthday state. Will return nil if none has
+// been set.
 func BirthState(dbtx walletdb.ReadTx) *BirthdayState {
 	ns := dbtx.ReadBucket(wtxmgrBucketKey)
 	const (

wallet/wallet_test.go

@@ -5,11 +5,16 @@
 package wallet
 
 import (
+	"context"
 	"encoding/hex"
+	"fmt"
 	"math"
 	"testing"
+	"time"
 
 	"decred.org/dcrwallet/v5/errors"
+	"decred.org/dcrwallet/v5/wallet/udb"
+	"github.com/decred/dcrd/chaincfg/chainhash"
 	"github.com/decred/dcrd/chaincfg/v3"
 )
 
@@ -138,3 +143,91 @@ func TestVotingXprivFromSeed(t *testing.T) {
 		}
 	}
 }
+
+func TestSetBirthStateAndScan(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	cfg := basicWalletConfig
+	w, teardown := testWallet(ctx, t, &cfg, nil)
+	defer teardown()
+
+	tg := maketg(t, cfg.Params)
+	tw := &tw{t, w}
+	forest := new(SidechainForest)
+
+	for i := 1; i < 10; i++ {
+		name := fmt.Sprintf("%va", i)
+		b := tg.nextBlock(name, nil, nil)
+		mustAddBlockNode(t, forest, b.BlockNode)
+		t.Logf("Generated block %v name %q", b.Hash, name)
+	}
+	b9aHash := tg.blockHashByName("9a")
+	bestChain := tw.evaluateBestChain(ctx, forest, 9, b9aHash)
+	tw.chainSwitch(ctx, forest, bestChain)
+	tw.assertNoBetterChain(ctx, forest)
+
+	tests := []struct {
+		name      string
+		bs        *udb.BirthdayState
+		wantBHash *chainhash.Hash
+		wantErr   bool
+	}{{
+		name: "ok middle",
+		bs: &udb.BirthdayState{
+			SetFromHeight: true,
+			Height:        6,
+		},
+		wantBHash: tg.blockHashByName("6a"),
+	}, {
+		name: "ok past tip",
+		bs: &udb.BirthdayState{
+			SetFromHeight: true,
+			Height:        20,
+		},
+		wantBHash: b9aHash,
+	}, {
+		name: "ok genesis",
+		bs: &udb.BirthdayState{
+			SetFromHeight: true,
+			Height:        0,
+		},
+		wantBHash: &cfg.Params.GenesisHash,
+	}, {
+		name: "ok from time",
+		bs: &udb.BirthdayState{
+			SetFromTime: true,
+			Time:        time.Now(),
+		},
+		wantBHash: b9aHash,
+	}, {
+		name:    "nil birthday passed",
+		wantErr: true,
+	}, {
+		name:    "nothing to set",
+		bs:      new(udb.BirthdayState),
+		wantErr: true,
+	}}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			err := w.SetBirthStateAndScan(ctx, test.bs)
+			if test.wantErr {
+				if err == nil {
+					t.Fatalf("expected error: %v", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			bs, err := w.BirthState(ctx)
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if bs.Hash != *test.wantBHash {
+				t.Fatalf("wanted birthday hash %v but got %v", test.wantBHash, bs.Hash)
+			}
+		})
+	}
+}