handle sensitivity in the OutputChange

The state is not loaded here with any marks, so we cannot rely on marks
alone for equality comparison. Compare both the state and the
configuration sensitivity before creating the OutputChange.

terraform/node_output.go

@@ -358,11 +358,13 @@ func (n *NodeDestroyableOutput) Execute(ctx EvalContext, op walkOperation) error
 
 	// if this is a root module, try to get a before value from the state for
 	// the diff
+	sensitiveBefore := false
 	before := cty.NullVal(cty.DynamicPseudoType)
 	mod := state.Module(n.Addr.Module)
 	if n.Addr.Module.IsRoot() && mod != nil {
 		for name, o := range mod.OutputValues {
 			if name == n.Addr.OutputValue.Name {
+				sensitiveBefore = o.Sensitive
 				before = o.Value
 				break
 			}
@@ -373,6 +375,7 @@ func (n *NodeDestroyableOutput) Execute(ctx EvalContext, op walkOperation) error
 	if changes != nil {
 		change := &plans.OutputChange{
 			Addr:      n.Addr,
+			Sensitive: sensitiveBefore,
 			Change: plans.Change{
 				Action: plans.Delete,
 				Before: before,
@@ -413,32 +416,51 @@ func (n *NodeApplyableOutput) setValue(state *states.SyncState, changes *plans.C
 	if changes != nil {
 		// if this is a root module, try to get a before value from the state for
 		// the diff
+		sensitiveBefore := false
 		before := cty.NullVal(cty.DynamicPseudoType)
 		mod := state.Module(n.Addr.Module)
 		if n.Addr.Module.IsRoot() && mod != nil {
 			for name, o := range mod.OutputValues {
 				if name == n.Addr.OutputValue.Name {
 					before = o.Value
+					sensitiveBefore = o.Sensitive
 					break
 				}
 			}
 		}
 
+		// We will not show the value is either the before or after are marked
+		// as sensitivity. We can show the value again once sensitivity is
+		// removed from both the config and the state.
+		sensitiveChange := sensitiveBefore || n.Config.Sensitive
+
+		// strip any marks here just to be sure we don't panic on the True comparison
+		val, _ = val.UnmarkDeep()
+
 		var action plans.Action
 		switch {
 		case val.IsNull():
 			action = plans.Delete
+
 		case before.IsNull():
 			action = plans.Create
-		case val.IsWhollyKnown() && val.Equals(before).True():
+
+		case val.IsWhollyKnown() &&
+			val.Equals(before).True() &&
+			n.Config.Sensitive == sensitiveBefore:
+			// Sensitivity must also match to be a NoOp.
+			// Theoretically marks may not match here, but sensitivity is the
+			// only one we can act on, and the state will have been loaded
+			// without any marks to consider.
 			action = plans.NoOp
+
 		default:
 			action = plans.Update
 		}
 
 		change := &plans.OutputChange{
 			Addr:      n.Addr,
-			Sensitive: n.Config.Sensitive,
+			Sensitive: sensitiveChange,
 			Change: plans.Change{
 				Action: action,
 				Before: before,

terraform/transform_output.go

@@ -47,8 +47,6 @@ func (t *OutputTransformer) transform(g *Graph, c *configs.Config) error {
 	// into NodeApplyableOutputs to reflect possible expansion
 	// through the presence of "count" or "for_each" on the modules.
 
-	// if this is a root output, we add the apply or destroy node directly, as
-	// the root modules does not expand
 	var changes []*plans.OutputChangeSrc
 	if t.Changes != nil {
 		changes = t.Changes.Outputs
@@ -69,6 +67,9 @@ func (t *OutputTransformer) transform(g *Graph, c *configs.Config) error {
 			destroy = rootChange.Action == plans.Delete
 		}
 
+		// If this is a root output, we add the apply or destroy node directly,
+		// as the root modules does not expand.
+
 		var node dag.Vertex
 		switch {
 		case c.Path.IsRoot() && destroy: