1 files changed, 29 insertions, 0 deletions
diff --git a/src/pkg/container/heap/heap_test.go b/src/pkg/container/heap/heap_test.go
index 274d587d8..b3d054c5f 100644
--- a/src/pkg/container/heap/heap_test.go
+++ b/src/pkg/container/heap/heap_test.go
@@ -5,6 +5,7 @@
 package heap
 
 import (
+	"math/rand"
 	"testing"
 )
 
@@ -182,3 +183,31 @@ func BenchmarkDup(b *testing.B) {
 		}
 	}
 }
+
+func TestFix(t *testing.T) {
+	h := new(myHeap)
+	h.verify(t, 0)
+
+	for i := 200; i > 0; i -= 10 {
+		Push(h, i)
+	}
+	h.verify(t, 0)
+
+	if (*h)[0] != 10 {
+		t.Fatalf("Expected head to be 10, was %d", (*h)[0])
+	}
+	(*h)[0] = 210
+	Fix(h, 0)
+	h.verify(t, 0)
+
+	for i := 100; i > 0; i-- {
+		elem := rand.Intn(h.Len())
+		if i&1 == 0 {
+			(*h)[elem] *= 2
+		} else {
+			(*h)[elem] /= 2
+		}
+		Fix(h, elem)
+		h.verify(t, 0)
+	}
+}