From 48676fe34b26b844ebc08b2b564ded0907df851d Mon Sep 17 00:00:00 2001
From: Natasha Sarkar <natashasarkar@google.com>
Date: Tue, 26 Jan 2021 16:42:59 -0800
Subject: [PATCH 1/3] updated patch delete test

---
 .../PatchStrategicMergeTransformer.go         |  3 +--
 api/krusty/patchdelete_test.go                | 24 +------------------
 2 files changed, 2 insertions(+), 25 deletions(-)

diff --git a/api/builtins/PatchStrategicMergeTransformer.go b/api/builtins/PatchStrategicMergeTransformer.go
index e94b8c4a2..77ebbc8ae 100644
--- a/api/builtins/PatchStrategicMergeTransformer.go
+++ b/api/builtins/PatchStrategicMergeTransformer.go
@@ -60,11 +60,10 @@ func (p *PatchStrategicMergeTransformerPlugin) Config(
 			"patch appears to be empty; files=%v, Patch=%s", p.Paths, p.Patches)
 	}
 	// Merge the patches, looking for conflicts.
-	m, err := h.ResmapFactory().ConflatePatches(p.loadedPatches)
+	_, err = h.ResmapFactory().ConflatePatches(p.loadedPatches)
 	if err != nil {
 		return err
 	}
-	p.loadedPatches = m.Resources()
 	return nil
 }
 
diff --git a/api/krusty/patchdelete_test.go b/api/krusty/patchdelete_test.go
index e0245c125..148f50d1b 100644
--- a/api/krusty/patchdelete_test.go
+++ b/api/krusty/patchdelete_test.go
@@ -69,28 +69,6 @@ spec:
         image: helloworld
         name: whatever
 `
-	// Allow expected variable to be unused
-	_ = expected
-
-	// Currently, kustomize inserts $patch: delete elements into the resulting resources
-	erroneousActual := `
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: whatever
-spec:
-  template:
-    spec:
-      containers:
-      - env:
-        - $patch: delete
-          name: NOT_EXISTING_FOR_REMOVAL
-        - name: EXISTING
-          value: EXISTING_VALUE
-        image: helloworld
-        name: whatever
-`
-
 	m := th.Run(".", th.MakeDefaultOptions())
-	th.AssertActualEqualsExpected(m, erroneousActual)
+	th.AssertActualEqualsExpected(m, expected)
 }

From 5958edda142cb2896c3a9875b4f8c86db67057fa Mon Sep 17 00:00:00 2001
From: Natasha Sarkar <natashasarkar@google.com>
Date: Tue, 26 Jan 2021 16:43:15 -0800
Subject: [PATCH 2/3] don't merge patches until they are applied

---
 .../PatchStrategicMergeTransformer.go                          | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/plugin/builtin/patchstrategicmergetransformer/PatchStrategicMergeTransformer.go b/plugin/builtin/patchstrategicmergetransformer/PatchStrategicMergeTransformer.go
index 59975d6b0..7a37c24ce 100644
--- a/plugin/builtin/patchstrategicmergetransformer/PatchStrategicMergeTransformer.go
+++ b/plugin/builtin/patchstrategicmergetransformer/PatchStrategicMergeTransformer.go
@@ -64,11 +64,10 @@ func (p *plugin) Config(
 			"patch appears to be empty; files=%v, Patch=%s", p.Paths, p.Patches)
 	}
 	// Merge the patches, looking for conflicts.
-	m, err := h.ResmapFactory().ConflatePatches(p.loadedPatches)
+	_, err = h.ResmapFactory().ConflatePatches(p.loadedPatches)
 	if err != nil {
 		return err
 	}
-	p.loadedPatches = m.Resources()
 	return nil
 }
 

From 4d5657f037e3cfc8d773f2fe29679a1fef527371 Mon Sep 17 00:00:00 2001
From: Natasha Sarkar <natashasarkar@google.com>
Date: Tue, 26 Jan 2021 16:43:30 -0800
Subject: [PATCH 3/3] smpdirectives shouldn't add elements when element isn't
 found

---
 kyaml/yaml/merge2/merge2.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kyaml/yaml/merge2/merge2.go b/kyaml/yaml/merge2/merge2.go
index 0a8c84487..d0625bd7c 100644
--- a/kyaml/yaml/merge2/merge2.go
+++ b/kyaml/yaml/merge2/merge2.go
@@ -59,6 +59,11 @@ func (m Merger) VisitMap(nodes walk.Sources, s *openapi.ResourceSchema) (*yaml.R
 	}
 	if yaml.IsMissingOrNull(nodes.Dest()) {
 		// Add
+		ps, _ := determineSmpDirective(nodes.Origin())
+		if ps == smpDelete {
+			return walk.ClearNode, nil
+		}
+
 		return nodes.Origin(), nil
 	}
 	if nodes.Origin().IsTaggedNull() {