From ad22e137e6aad7b5c3aa442e8aaaaef77384a4b1 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Fri, 4 Sep 2020 15:59:22 -0400
Subject: [PATCH] Get the new RefreshState into the right contexts

---
 terraform/context.go            | 34 ++++++++++++++++++++++-----------
 terraform/graph_walk_context.go |  2 ++
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/terraform/context.go b/terraform/context.go
index 4156aa1f0..8afba75cd 100644
--- a/terraform/context.go
+++ b/terraform/context.go
@@ -781,20 +781,32 @@ func (c *Context) walk(graph *Graph, operation walkOperation) (*ContextGraphWalk
 }
 
 func (c *Context) graphWalker(operation walkOperation) *ContextGraphWalker {
-	if operation == walkValidate {
-		return &ContextGraphWalker{
-			Context:            c,
-			State:              states.NewState().SyncWrapper(),
-			Changes:            c.changes.SyncWrapper(),
-			InstanceExpander:   instances.NewExpander(),
-			Operation:          operation,
-			StopContext:        c.runContext,
-			RootVariableValues: c.variables,
-		}
+	var state *states.SyncState
+	var refreshState *states.SyncState
+
+	switch operation {
+	case walkValidate:
+		// validate should not use any state
+		s := states.NewState()
+		state = s.SyncWrapper()
+
+		// validate currently uses the plan graph, so we have to populate the
+		// refreshState.
+		refreshState = s.SyncWrapper()
+
+	case walkPlan:
+		state = c.state.SyncWrapper()
+		// plan requires a second state to store the refreshed resources
+		refreshState = c.state.DeepCopy().SyncWrapper()
+
+	default:
+		state = c.state.SyncWrapper()
 	}
+
 	return &ContextGraphWalker{
 		Context:            c,
-		State:              c.state.SyncWrapper(),
+		State:              state,
+		RefreshState:       refreshState,
 		Changes:            c.changes.SyncWrapper(),
 		InstanceExpander:   instances.NewExpander(),
 		Operation:          operation,
diff --git a/terraform/graph_walk_context.go b/terraform/graph_walk_context.go
index c842c0af4..d3ca73b3f 100644
--- a/terraform/graph_walk_context.go
+++ b/terraform/graph_walk_context.go
@@ -26,6 +26,7 @@ type ContextGraphWalker struct {
 	// Configurable values
 	Context            *Context
 	State              *states.SyncState   // Used for safe concurrent access to state
+	RefreshState       *states.SyncState   // Used for safe concurrent access to state
 	Changes            *plans.ChangesSync  // Used for safe concurrent writes to changes
 	InstanceExpander   *instances.Expander // Tracks our gradual expansion of module and resource instances
 	Operation          walkOperation
@@ -96,6 +97,7 @@ func (w *ContextGraphWalker) EvalContext() EvalContext {
 		ProvisionerLock:       &w.provisionerLock,
 		ChangesValue:          w.Changes,
 		StateValue:            w.State,
+		RefreshStateValue:     w.RefreshState,
 		Evaluator:             evaluator,
 		VariableValues:        w.variableValues,
 		VariableValuesLock:    &w.variableValuesLock,