Fix updating the UTXO set for imported addresses

Wallet would fail to update UTXOs for imported address outputs while
rescanning after using importprivkey or importscript if the transaction
already existed in the database. The new code is rearranged to always
update spending data even if the transaction already exists.

Fixes #132.

wtxmgr/tx.go

@@ -804,52 +804,7 @@ func (s *Store) InsertTx(rec *TxRecord, block *BlockMeta) error {
 // are removed.
 func (s *Store) insertMinedTx(ns walletdb.Bucket, rec *TxRecord,
 	block *BlockMeta) error {
-	// If a transaction record for this tx hash and block already exist,
-	// there is nothing left to do.
-	k, v := existsTxRecord(ns, &rec.Hash, &block.Block)
-	if v != nil {
-		return nil
-	}
-
-	// If the exact tx (not a double spend) is already included but
-	// unconfirmed, move it to a block.
-	v = existsRawUnmined(ns, rec.Hash[:])
-	if v != nil {
-		return s.moveMinedTx(ns, rec, k, v, block)
-	}
-
-	// As there may be unconfirmed transactions that are invalidated by this
-	// transaction (either being duplicates, or double spends), remove them
-	// from the unconfirmed set.  This also handles removing unconfirmed
-	// transaction spend chains if any other unconfirmed transactions spend
-	// outputs of the removed double spend.
-	err := s.removeDoubleSpends(ns, rec)
-	if err != nil {
-		return err
-	}
-
-	// If a block record does not yet exist for any transactions from this
-	// block, insert the record.  Otherwise, update it by adding the
-	// transaction hash to the set of transactions from this block.
-	blockKey, blockValue := existsBlockRecord(ns, block.Height)
-	if blockValue == nil {
-		err = putBlockRecord(ns, block, &rec.Hash)
-	} else {
-		blockValue, err = appendRawBlockRecord(blockValue, &rec.Hash)
-		if err != nil {
-			return err
-		}
-		err = putRawBlockRecord(ns, blockKey, blockValue)
-	}
-	if err != nil {
-		return err
-	}
-
-	err = putTxRecord(ns, rec, &block.Block)
-	if err != nil {
-		return err
-	}
-
+	// Fetch the mined balance in case we need to update it.
 	minedBalance, err := fetchMinedBalance(ns)
 	if err != nil {
 		return err
@@ -910,7 +865,60 @@ func (s *Store) insertMinedTx(ns walletdb.Bucket, rec *TxRecord,
 		}
 	}
 
-	return putMinedBalance(ns, minedBalance)
+	// TODO only update if we actually modified the
+	// mined balance.
+	err = putMinedBalance(ns, minedBalance)
+	if err != nil {
+		return nil
+	}
+
+	// If a transaction record for this tx hash and block already exist,
+	// there is nothing left to do.
+	k, v := existsTxRecord(ns, &rec.Hash, &block.Block)
+	if v != nil {
+		return nil
+	}
+
+	// If the exact tx (not a double spend) is already included but
+	// unconfirmed, move it to a block.
+	v = existsRawUnmined(ns, rec.Hash[:])
+	if v != nil {
+		return s.moveMinedTx(ns, rec, k, v, block)
+	}
+
+	// As there may be unconfirmed transactions that are invalidated by this
+	// transaction (either being duplicates, or double spends), remove them
+	// from the unconfirmed set.  This also handles removing unconfirmed
+	// transaction spend chains if any other unconfirmed transactions spend
+	// outputs of the removed double spend.
+	err = s.removeDoubleSpends(ns, rec)
+	if err != nil {
+		return err
+	}
+
+	// If a block record does not yet exist for any transactions from this
+	// block, insert the record.  Otherwise, update it by adding the
+	// transaction hash to the set of transactions from this block.
+	blockKey, blockValue := existsBlockRecord(ns, block.Height)
+	if blockValue == nil {
+		err = putBlockRecord(ns, block, &rec.Hash)
+	} else {
+		blockValue, err = appendRawBlockRecord(blockValue, &rec.Hash)
+		if err != nil {
+			return err
+		}
+		err = putRawBlockRecord(ns, blockKey, blockValue)
+	}
+	if err != nil {
+		return err
+	}
+
+	err = putTxRecord(ns, rec, &block.Block)
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 // AddCredit marks a transaction record as containing a transaction output