params: better handle nil and large timestamps

Author: holiman

params/config.go

@@ -1020,8 +1020,8 @@ func (c *ChainConfig) Rules(num *big.Int, isMerge bool, timestamp *big.Int) Rule
 		IsBerlin:         c.IsBerlin(num),
 		IsLondon:         c.IsLondon(num),
 		IsMerge:          isMerge,
-		IsShanghai:       timestamp.IsUint64() && c.IsShanghai(timestamp.Uint64()),
-		isCancun:         timestamp.IsUint64() && c.IsCancun(timestamp.Uint64()),
-		isPrague:         timestamp.IsUint64() && c.IsPrague(timestamp.Uint64()),
+		IsShanghai:       timestamp != nil && (!timestamp.IsUint64() || c.IsShanghai(timestamp.Uint64())),
+		isCancun:         timestamp != nil && (!timestamp.IsUint64() || c.IsCancun(timestamp.Uint64())),
+		isPrague:         timestamp != nil && (!timestamp.IsUint64() || c.IsPrague(timestamp.Uint64())),
 	}
 }

params/config_test.go

@@ -116,3 +116,25 @@ func TestCheckCompatible(t *testing.T) {
 		}
 	}
 }
+
+func TestConfigRules(t *testing.T) {
+	c := &ChainConfig{
+		ShanghaiTime: big.NewInt(500),
+	}
+	var stamp *big.Int
+	if r := c.Rules(big.NewInt(0), true, stamp); r.IsShanghai {
+		t.Errorf("expected %v to not be shanghai", stamp)
+	}
+	stamp = big.NewInt(0)
+	if r := c.Rules(big.NewInt(0), true, stamp); r.IsShanghai {
+		t.Errorf("expected %v to not be shanghai", stamp)
+	}
+	stamp = big.NewInt(500)
+	if r := c.Rules(big.NewInt(0), true, stamp); !r.IsShanghai {
+		t.Errorf("expected %v to be shanghai", stamp)
+	}
+	stamp, _ = big.NewInt(0).SetString("0xffffffff0000000000000000000000000000000000000000", 0)
+	if r := c.Rules(big.NewInt(0), true, stamp); !r.IsShanghai {
+		t.Errorf("expected %v to be shanghai", stamp)
+	}
+}