From 0f3d9ee624282b84765993f25ab17f10da18d5c8 Mon Sep 17 00:00:00 2001
From: Todd Gruben <todd@pilosa.com>
Date: Mon, 13 Sep 2021 17:30:33 -0500
Subject: [PATCH] backport 1697

---
 api.go      | 8 ++++----
 api_test.go | 8 +++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/api.go b/api.go
index 2ce422608..dda49c8ba 100644
--- a/api.go
+++ b/api.go
@@ -2219,9 +2219,9 @@ func mergeIDLists(dst []uint64, src []uint64) []uint64 {
 		return dst[i] < dst[j]
 	})
 	// dedup.
-	n := 0
+	n := 1
 	prev := dst[0]
-	for i := 0; i < len(dst); i++ {
+	for i := 1; i < len(dst); i++ {
 		if dst[i] != prev {
 			dst[n] = dst[i]
 			n++
@@ -2239,9 +2239,9 @@ func mergeKeyLists(dst []string, src []string) []string {
 		return dst[i] < dst[j]
 	})
 	// dedup.
-	n := 0
+	n := 1
 	prev := dst[0]
-	for i := 0; i < len(dst); i++ {
+	for i := 1; i < len(dst); i++ {
 		if dst[i] != prev {
 			dst[n] = dst[i]
 			n++
diff --git a/api_test.go b/api_test.go
index d5b1d26a4..ef4de9fca 100644
--- a/api_test.go
+++ b/api_test.go
@@ -638,7 +638,13 @@ type mutexCheckField struct {
 }
 
 func TestAPI_MutexCheck(t *testing.T) {
-	c := test.MustRunCluster(t, 3)
+	c := test.MustNewCluster(t, 3)
+	for _, c := range c.Nodes {
+		c.Config.Cluster.ReplicaN = 2
+	}
+	if err := c.Start(); err != nil {
+		t.Fatalf("starting cluster: %v", err)
+	}
 	defer c.Close()
 
 	m0 := c.GetNode(0)