core/state: abort commit if errors have occurred (#484)

core/state/statedb.go

@@ -649,6 +649,10 @@ func (s *StateDB) clearJournalAndRefund() {
 
 // Commit writes the state to the underlying in-memory trie database.
 func (s *StateDB) Commit(deleteEmptyObjects bool) (root common.Hash, err error) {
+	if s.dbErr != nil {
+		return common.Hash{}, fmt.Errorf("commit aborted due to earlier error: %v", s.dbErr)
+	}
+	
 	defer s.clearJournalAndRefund()
 
 	// Commit objects to the trie.

core/state/statedb_test.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
-	"github.com/XinFinOrg/XDPoSChain/core/rawdb"
 	"math"
 	"math/big"
 	"math/rand"
@@ -29,6 +28,8 @@ import (
 	"testing"
 	"testing/quick"
 
+	"github.com/XinFinOrg/XDPoSChain/core/rawdb"
+
 	check "gopkg.in/check.v1"
 
 	"github.com/XinFinOrg/XDPoSChain/common"
@@ -427,3 +428,51 @@ func (s *StateSuite) TestTouchDelete(c *check.C) {
 		c.Fatal("expected no dirty state object")
 	}
 }
+
+// TestMissingTrieNodes tests that if the statedb fails to load parts of the trie,
+// the Commit operation fails with an error
+// If we are missing trie nodes, we should not continue writing to the trie
+func TestMissingTrieNodes(t *testing.T) {
+
+	// Create an initial state with a few accounts
+	memDb := rawdb.NewMemoryDatabase()
+	db := NewDatabase(memDb)
+	var root common.Hash
+	state, _ := New(common.Hash{}, db)
+	addr := toAddr([]byte("so"))
+	{
+		state.SetBalance(addr, big.NewInt(1))
+		state.SetCode(addr, []byte{1, 2, 3})
+		a2 := toAddr([]byte("another"))
+		state.SetBalance(a2, big.NewInt(100))
+		state.SetCode(a2, []byte{1, 2, 4})
+		root, _ = state.Commit(false)
+		t.Logf("root: %x", root)
+		// force-flush
+		state.Database().TrieDB().Cap(0)
+	}
+	// Create a new state on the old root
+	state, _ = New(root, db)
+	//state, _ = New(root, db, nil)
+	// Now we clear out the memdb
+	it := memDb.NewIterator(nil, nil)
+	for it.Next() {
+		k := it.Key()
+		// Leave the root intact
+		if !bytes.Equal(k, root[:]) {
+			t.Logf("key: %x", k)
+			memDb.Delete(k)
+		}
+	}
+	balance := state.GetBalance(addr)
+	// The removed elem should lead to it returning zero balance
+	if exp, got := uint64(0), balance.Uint64(); got != exp {
+		t.Errorf("expected %d, got %d", exp, got)
+	}
+	// Modify the state
+	state.SetBalance(addr, big.NewInt(2))
+	root, err := state.Commit(false)
+	if err == nil {
+		t.Fatalf("expected error, got root :%x", root)
+	}
+}