terraform: when promoting non-CBD to CBD, mark the config as such

Fixes #10439

When a CBD resource depends on a non-CBD resource, the non-CBD resource
is auto-promoted to CBD. This was done in
cf3a259. This PR makes it so that we
also set the config CBD to true. This causes the proper runtime
execution behavior to occur where we depose state and so on.

So in addition to simple graph edge tricks we also treat the non-CBD
resources as CBD resources.

terraform/context_apply_test.go

@@ -881,6 +881,73 @@ func TestContext2Apply_createBeforeDestroyUpdate(t *testing.T) {
 	}
 }
 
+// This tests that when a CBD resource depends on a non-CBD resource,
+// we can still properly apply changes that require new for both.
+func TestContext2Apply_createBeforeDestroy_dependsNonCBD(t *testing.T) {
+	m := testModule(t, "apply-cbd-depends-non-cbd")
+	p := testProvider("aws")
+	p.ApplyFn = testApplyFn
+	p.DiffFn = testDiffFn
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.bar": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "bar",
+							Attributes: map[string]string{
+								"require_new": "abc",
+							},
+						},
+					},
+
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+							Attributes: map[string]string{
+								"require_new": "abc",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+		State: state,
+	})
+
+	if p, err := ctx.Plan(); err != nil {
+		t.Fatalf("err: %s", err)
+	} else {
+		t.Logf(p.String())
+	}
+
+	state, err := ctx.Apply()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	checkStateString(t, state, `
+aws_instance.bar:
+  ID = foo
+  require_new = yes
+  type = aws_instance
+  value = foo
+aws_instance.foo:
+  ID = foo
+  require_new = yes
+  type = aws_instance
+	`)
+}
+
 func TestContext2Apply_createBeforeDestroy_hook(t *testing.T) {
 	h := new(MockHook)
 	m := testModule(t, "apply-good-create-before")

terraform/test-fixtures/apply-cbd-depends-non-cbd/main.tf

@@ -0,0 +1,12 @@
+resource "aws_instance" "foo" {
+  require_new = "yes"
+}
+
+resource "aws_instance" "bar" {
+  require_new = "yes"
+  value       = "${aws_instance.foo.id}"
+
+  lifecycle {
+    create_before_destroy = true
+  }
+}

terraform/transform_destroy.go

@@ -1,6 +1,9 @@
 package terraform
 
-import "github.com/hashicorp/terraform/dag"
+import (
+	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/dag"
+)
 
 // GraphNodeDestroyable is the interface that nodes that can be destroyed
 // must implement. This is used to automatically handle the creation of
@@ -151,8 +154,28 @@ func (t *CreateBeforeDestroyTransformer) Transform(g *Graph) error {
 		}
 
 		// If the node doesn't need to create before destroy, then continue
-		if !dn.CreateBeforeDestroy() && noCreateBeforeDestroyAncestors(g, dn) {
-			continue
+		if !dn.CreateBeforeDestroy() {
+			if noCreateBeforeDestroyAncestors(g, dn) {
+				continue
+			}
+
+			// PURPOSELY HACKY FIX SINCE THIS TRANSFORM IS DEPRECATED.
+			// This is a hacky way to fix GH-10439. For a detailed description
+			// of the fix, see CBDEdgeTransformer, which is the equivalent
+			// transform used by the new graphs.
+			//
+			// This transform is deprecated because it is only used by the
+			// old graphs which are going to be removed.
+			var update *config.Resource
+			if dn, ok := v.(*graphNodeResourceDestroy); ok {
+				update = dn.Original.Resource
+			}
+			if dn, ok := v.(*graphNodeResourceDestroyFlat); ok {
+				update = dn.Original.Resource
+			}
+			if update != nil {
+				update.Lifecycle.CreateBeforeDestroy = true
+			}
 		}
 
 		// Get the creation side of this node