1 files changed, 38 insertions, 0 deletions
diff --git a/libgo/go/crypto/elliptic/elliptic_test.go b/libgo/go/crypto/elliptic/elliptic_test.go
index 1e3407ee0e7..58f903966ce 100644
--- a/libgo/go/crypto/elliptic/elliptic_test.go
+++ b/libgo/go/crypto/elliptic/elliptic_test.go
@@ -322,6 +322,44 @@ func TestGenericBaseMult(t *testing.T) {
 	}
 }
 
+func TestInfinity(t *testing.T) {
+	tests := []struct {
+		name  string
+		curve Curve
+	}{
+		{"p224", P224()},
+		{"p256", P256()},
+	}
+
+	for _, test := range tests {
+		curve := test.curve
+		x, y := curve.ScalarBaseMult(nil)
+		if x.Sign() != 0 || y.Sign() != 0 {
+			t.Errorf("%s: x^0 != ∞", test.name)
+		}
+		x.SetInt64(0)
+		y.SetInt64(0)
+
+		x2, y2 := curve.Double(x, y)
+		if x2.Sign() != 0 || y2.Sign() != 0 {
+			t.Errorf("%s: 2∞ != ∞", test.name)
+		}
+
+		baseX := curve.Params().Gx
+		baseY := curve.Params().Gy
+
+		x3, y3 := curve.Add(baseX, baseY, x, y)
+		if x3.Cmp(baseX) != 0 || y3.Cmp(baseY) != 0 {
+			t.Errorf("%s: x+∞ != x", test.name)
+		}
+
+		x4, y4 := curve.Add(x, y, baseX, baseY)
+		if x4.Cmp(baseX) != 0 || y4.Cmp(baseY) != 0 {
+			t.Errorf("%s: ∞+x != x", test.name)
+		}
+	}
+}
+
 func BenchmarkBaseMult(b *testing.B) {
 	b.ResetTimer()
 	p224 := P224()