From 20924b3caaad0158930f113fd6d361eb20ff54c5 Mon Sep 17 00:00:00 2001
From: Arkadiusz Osowski <arkadiusz.osowski@4chain.studio>
Date: Fri, 26 Apr 2024 12:23:48 +0200
Subject: [PATCH] fix(SPV-769): check sql.select results length

---
 database/sql/headers.go   | 15 ++++++++-------
 service/header_service.go |  4 ++--
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/database/sql/headers.go b/database/sql/headers.go
index 0bccab38..4a6d9271 100644
--- a/database/sql/headers.go
+++ b/database/sql/headers.go
@@ -335,6 +335,10 @@ func (h *HeadersDb) GetTip(ctx context.Context) (*dto.DbBlockHeader, error) {
 		h.log.Error().Msgf("sql error: %v", err)
 		return nil, errors.Wrap(err, "failed to get tip")
 	}
+	if len(tip) == 0 {
+		return nil, errors.New("could not find tip")
+	}
+
 	return &tip[0], nil
 }
 
@@ -342,12 +346,9 @@ func (h *HeadersDb) GetTip(ctx context.Context) (*dto.DbBlockHeader, error) {
 func (h *HeadersDb) GetAncestorOnHeight(hash string, height int32) (*dto.DbBlockHeader, error) {
 	var bh []*dto.DbBlockHeader
 	if err := h.db.Select(&bh, h.db.Rebind(sqlSelectAncestorOnHeight), hash, int(height), int(height)); err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return nil, errors.New("could not find ancestors for a providen hash")
-		}
 		return nil, errors.Wrapf(err, "failed to get ancestors using given hash: %s ", hash)
 	}
-	if bh == nil {
+	if len(bh) == 0 {
 		return nil, errors.New("could not find ancestors for a providen hash")
 	}
 	return bh[0], nil
@@ -366,11 +367,11 @@ func (h *HeadersDb) GetAllTips() ([]*dto.DbBlockHeader, error) {
 func (h *HeadersDb) GetChainBetweenTwoHashes(low string, high string) ([]*dto.DbBlockHeader, error) {
 	var bh []*dto.DbBlockHeader
 	if err := h.db.Select(&bh, h.db.Rebind(sqlChainBetweenTwoHashes), high, low, low); err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return nil, errors.New("could not find headers in given range")
-		}
 		return nil, errors.Wrapf(err, "failed to get headers using given range from: %s to: %s", low, high)
 	}
+	if len(bh) == 0 {
+		return nil, errors.New("could not find headers in given range")
+	}
 	return bh, nil
 }
 
diff --git a/service/header_service.go b/service/header_service.go
index 3614b7e2..60f989e6 100644
--- a/service/header_service.go
+++ b/service/header_service.go
@@ -66,12 +66,12 @@ func (hs *HeaderService) IsCurrent() bool {
 	// Not current if the latest main (best) chain height is before the
 	// latest known good checkpoint (when checkpoints are enabled).
 	checkpoints := hs.checkpoints
-	checkpoint := &checkpoints[len(checkpoints)-1]
+	checkpoint := checkpoints[len(checkpoints)-1]
 	tip := hs.GetTip()
 	if tip == nil {
 		return true
 	}
-	if checkpoint != nil && tip.Height < checkpoint.Height {
+	if tip.Height < checkpoint.Height {
 		return false
 	}