Revert "Make sure inner state summary accept is called (#3831)"

snow/engine/snowman/block/state_summary.go

@@ -21,14 +21,8 @@ type StateSummary interface {
 	// Bytes returns a byte slice than can be used to reconstruct this summary.
 	Bytes() []byte
 
-	// Accept notifies the VM that this is a canonically accepted state summary.
-	// The VM is expected to return how it plans on handling this summary via
-	// the [StateSyncMode].
+	// Accept triggers the VM to start state syncing to this summary.
 	//
-	// Invariant: The VM must be able to correctly handle the acceptance of a
-	// state summary that is older than its current state.
-	//
-	// See [StateSyncSkipped], [StateSyncStatic], and [StateSyncDynamic] for the
-	// expected invariants the VM must maintain based on the return value.
+	// It returns the state sync mode selected by the VM.
 	Accept(context.Context) (StateSyncMode, error)
 }

vms/proposervm/state_summary.go

@@ -40,6 +40,12 @@ func (s *stateSummary) Height() uint64 {
 }
 
 func (s *stateSummary) Accept(ctx context.Context) (block.StateSyncMode, error) {
+	// If we have already synced up to or past this state summary, we do not
+	// want to sync to it.
+	if s.vm.lastAcceptedHeight >= s.Height() {
+		return block.StateSyncSkipped, nil
+	}
+
 	// set fork height first, before accepting proposerVM full block
 	// which updates height index (among other indices)
 	if err := s.vm.State.SetForkHeight(s.StateSummary.ForkHeight()); err != nil {
@@ -56,8 +62,5 @@ func (s *stateSummary) Accept(ctx context.Context) (block.StateSyncMode, error)
 	// innerSummary.Accept may fail with the proposerVM block and index already
 	// updated. The error would be treated as fatal and the chain would then be
 	// repaired upon the VM restart.
-	// After the inner summary is accepted, the engine transitions to bootstrapping
-	// and SetState is responsible for re-aligning the ProposerVM to the height reported
-	// by the inner VM after handling state sync.
 	return s.innerSummary.Accept(ctx)
 }

vms/proposervm/state_syncable_vm_test.go

@@ -83,7 +83,6 @@ func helperBuildStateSyncTestObjects(t *testing.T) (*fullVM, *VM) {
 		nil,
 		nil,
 	))
-	require.NoError(vm.SetState(context.Background(), snow.StateSyncing))
 
 	return innerVM, vm
 }
@@ -565,28 +564,12 @@ func TestStateSummaryAcceptOlderBlock(t *testing.T) {
 
 	summary, err := vm.GetStateSummary(context.Background(), reqHeight)
 	require.NoError(err)
-	require.Equal(summary.Height(), reqHeight)
 
-	// test Accept summary invokes innerVM
-	calledInnerAccept := false
+	// test Accept skipped
 	innerSummary.AcceptF = func(context.Context) (block.StateSyncMode, error) {
-		innerVM.LastAcceptedF = func(context.Context) (ids.ID, error) {
-			return innerSummary.ID(), nil
-		}
-		innerVM.GetBlockF = func(context.Context, ids.ID) (snowman.Block, error) {
-			return innerBlk, nil
-		}
-		calledInnerAccept = true
 		return block.StateSyncStatic, nil
 	}
 	status, err := summary.Accept(context.Background())
 	require.NoError(err)
-	require.Equal(block.StateSyncStatic, status)
-	require.True(calledInnerAccept)
-
-	require.NoError(vm.SetState(context.Background(), snow.Bootstrapping))
-	require.Equal(summary.Height(), vm.lastAcceptedHeight)
-	lastAcceptedID, err := vm.LastAccepted(context.Background())
-	require.NoError(err)
-	require.Equal(proBlk.ID(), lastAcceptedID)
+	require.Equal(block.StateSyncSkipped, status)
 }