fix: wrong variable usage

redblack.go

@@ -22,7 +22,7 @@ func (t *Tree) rightRotate(node *Node) {
 		left = node.left
 	)
 
-	node.left = node.right
+	node.left = left.right
 	if node.left != nil {
 		node.left.parent = node
 	}
@@ -88,7 +88,7 @@ func (t *Tree) fixup(root, pt *Node) {
 		unclePt       *Node
 	)
 
-	for pt != t.root && pt.color != 0 && pt.parent.color == 1 {
+	for pt != root && pt.color != 0 && pt.parent.color == 1 {
 		parentPt = pt.parent
 		grandParentPt = pt.parent.parent
 

redblack_test.go

@@ -1,6 +1,10 @@
 package redblack
 
-import "testing"
+import (
+	"math/rand"
+	"testing"
+	"time"
+)
 
 type testKey int
 
@@ -12,22 +16,44 @@ func (k testKey) Compare(c Comparable) int {
 	panic("unexpected type")
 }
 
+func TestMulti(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		TestInsert(t)
+	}
+}
+
 func TestInsert(t *testing.T) {
 	var (
-		tree *Tree
-		out  []Comparable
-		keys = []testKey{7, 6, 5, 4, 3, 2, 1}
+		tree  *Tree
+		out   []Comparable
+		keys  []testKey
+		input []testKey
 	)
 
+	keys = make([]testKey, 1000000)
+	for i := range keys {
+		keys[i] = testKey(i + 1)
+	}
+	//t.Log("base:", keys)
+	input = make([]testKey, len(keys))
+	copy(input, keys)
+
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	r.Shuffle(len(input), func(i, j int) {
+		input[i], input[j] = input[j], input[i]
+	})
+	//t.Log("shuffled:", input)
+
 	tree = new(Tree)
-	for _, k := range keys {
+	for _, k := range input {
 		tree.Insert(k)
 	}
 
 	out = tree.Slice()
+	//t.Log("output:", out)
 	for i, d := range out {
 		if ck, ok := d.(testKey); ok {
-			if ck != keys[len(keys)-1-i] {
+			if ck != keys[i] {
 				t.Fatal("mismatch data")
 			}
 		} else {