From 29268467f9dbada1eaceb4bc251fe4ad9597c906 Mon Sep 17 00:00:00 2001
From: jholdstock <jholdstock@decred.org>
Date: Mon, 15 Jun 2020 12:10:10 +0100
Subject: [PATCH] Delete tickets with no information.

---
 background/background.go  | 24 +++++++++++++++++++++++-
 database/database_test.go |  1 +
 database/ticket.go        | 12 ++++++++++++
 database/ticket_test.go   | 24 ++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/background/background.go b/background/background.go
index 4c399ce..0723b87 100644
--- a/background/background.go
+++ b/background/background.go
@@ -3,6 +3,7 @@ package background
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"sync"
 	"time"
 
@@ -10,6 +11,7 @@ import (
 	"github.com/decred/dcrd/chaincfg/v3"
 	"github.com/decred/vspd/database"
 	"github.com/decred/vspd/rpc"
+	"github.com/jrick/wsrpc/v2"
 )
 
 var (
@@ -28,6 +30,9 @@ const (
 	// requiredConfs is the number of confirmations required to consider a
 	// ticket purchase or a fee transaction to be final.
 	requiredConfs = 6
+	// errNoTxInfo is defined in dcrd/dcrjson. Copying here so we dont need to
+	// import the whole package.
+	errNoTxInfo = -5
 )
 
 // Notify is called every time a block notification is received from dcrd.
@@ -76,9 +81,26 @@ func blockConnected() {
 	for _, ticket := range unconfirmed {
 		tktTx, err := dcrdClient.GetRawTransaction(ticket.Hash)
 		if err != nil {
-			log.Errorf("GetRawTransaction error: %v", err)
+			// errNoTxInfo here probably indicates a tx which was never mined
+			// and has been removed from the mempool. For example, a ticket
+			// purchase tx close to an sdiff change, or a ticket purchase tx
+			// which expired. Remove it from the db.
+			var e *wsrpc.Error
+			if errors.As(err, &e) && e.Code == errNoTxInfo {
+				log.Infof("Removing unconfirmed ticket from db - no information available "+
+					"about transaction %s", err.Error())
+
+				err = db.DeleteTicket(ticket)
+				if err != nil {
+					log.Errorf("DeleteTicket error: %v", err)
+				}
+			} else {
+				log.Errorf("GetRawTransaction error: %v", err)
+			}
+
 			continue
 		}
+
 		if tktTx.Confirmations >= requiredConfs {
 			ticket.Confirmed = true
 			err = db.UpdateTicket(ticket)
diff --git a/database/database_test.go b/database/database_test.go
index c85e322..4032753 100644
--- a/database/database_test.go
+++ b/database/database_test.go
@@ -28,6 +28,7 @@ func TestDatabase(t *testing.T) {
 		"testTicketFeeExpired": testTicketFeeExpired,
 		"testFilterTickets":    testFilterTickets,
 		"testAddressIndex":     testAddressIndex,
+		"testDeleteTicket":     testDeleteTicket,
 	}
 
 	for testName, test := range tests {
diff --git a/database/ticket.go b/database/ticket.go
index 2010970..06cb4c3 100644
--- a/database/ticket.go
+++ b/database/ticket.go
@@ -103,6 +103,18 @@ func (vdb *VspDatabase) InsertNewTicket(ticket Ticket) error {
 	})
 }
 
+func (vdb *VspDatabase) DeleteTicket(ticket Ticket) error {
+	return vdb.db.Update(func(tx *bolt.Tx) error {
+		ticketBkt := tx.Bucket(vspBktK).Bucket(ticketBktK)
+
+		err := ticketBkt.Delete([]byte(ticket.Hash))
+		if err != nil {
+			return fmt.Errorf("could not delete ticket: %v", err)
+		}
+
+		return nil
+	})
+}
 func (vdb *VspDatabase) UpdateTicket(ticket Ticket) error {
 	return vdb.db.Update(func(tx *bolt.Tx) error {
 		ticketBkt := tx.Bucket(vspBktK).Bucket(ticketBktK)
diff --git a/database/ticket_test.go b/database/ticket_test.go
index 18fc543..482baed 100644
--- a/database/ticket_test.go
+++ b/database/ticket_test.go
@@ -55,6 +55,30 @@ func testInsertNewTicket(t *testing.T) {
 	}
 }
 
+func testDeleteTicket(t *testing.T) {
+	// Insert a ticket into the database.
+	ticket := exampleTicket()
+	err := db.InsertNewTicket(ticket)
+	if err != nil {
+		t.Fatalf("error storing ticket in database: %v", err)
+	}
+
+	// Delete ticket
+	err = db.DeleteTicket(ticket)
+	if err != nil {
+		t.Fatalf("error deleting ticket: %v", err)
+	}
+
+	// Nothing should be in the db.
+	_, found, err := db.GetTicketByHash(ticket.Hash)
+	if err != nil {
+		t.Fatalf("error retrieving ticket by ticket hash: %v", err)
+	}
+	if found {
+		t.Fatal("expected found==false")
+	}
+}
+
 func testGetTicketByHash(t *testing.T) {
 	ticket := exampleTicket()
 	// Insert a ticket into the database.