accounts/abi/bind/backends: fix AdjustTime to respect Fork (#25225)

accounts/abi/bind/backends/simulated.go

@@ -793,8 +793,13 @@ func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
 	if len(b.pendingBlock.Transactions()) != 0 {
 		return errors.New("Could not adjust time on non-empty block")
 	}
+	// Get the last block
+	block := b.blockchain.GetBlockByHash(b.pendingBlock.ParentHash())
+	if block == nil {
+		return fmt.Errorf("could not find parent")
+	}
 
-	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
+	blocks, _ := core.GenerateChain(b.config, block, ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
 		block.OffsetTime(int64(adjustment.Seconds()))
 	})
 	stateDB, _ := b.blockchain.State()

accounts/abi/bind/backends/simulated_test.go

@@ -1377,3 +1377,23 @@ func TestCommitReturnValue(t *testing.T) {
 		t.Error("Could not retrieve the just created block (side-chain)")
 	}
 }
+
+// TestAdjustTimeAfterFork ensures that after a fork, AdjustTime uses the pending fork
+// block's parent rather than the canonical head's parent.
+func TestAdjustTimeAfterFork(t *testing.T) {
+	testAddr := crypto.PubkeyToAddress(testKey.PublicKey)
+	sim := simTestBackend(testAddr)
+	defer sim.Close()
+
+	sim.Commit() // h1
+	h1 := sim.blockchain.CurrentHeader().Hash()
+	sim.Commit() // h2
+	sim.Fork(context.Background(), h1)
+	sim.AdjustTime(1 * time.Second)
+	sim.Commit()
+
+	head := sim.blockchain.CurrentHeader()
+	if head.Number == common.Big2 && head.ParentHash != h1 {
+		t.Errorf("failed to build block on fork")
+	}
+}