kustomize: Regression: PatchTransformer alters the name of ports that have matching containerPort values

When a deployment has a container with two differently-named ports that match on the containerPort, a PatchTransformer alters the name of the second port so that it matches the first.

Affected versions

{Version:kustomize/v3.8.0 GitCommit:6a50372dd5686df22750b0c729adaf369fbf193c BuildDate:2020-07-05T14:08:42Z GoOs:linux GoArch:amd64}

and

{Version:kustomize/v3.8.1 GitCommit:0b359d0ef0272e6545eda0e99aacd63aef99c4d0 BuildDate:2020-07-16T00:58:46Z GoOs:linux GoArch:amd64}

Test setup

kustomization.yaml

resources:
  - resources.yaml

transformers:
  - transformers.yaml

resources.yaml

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-deployment
spec:
  template:
    spec:
      containers:
      - image: test-image
        name: test-deployment
        ports:
        - containerPort: 8080
          name: take-over-the-world
          protocol: TCP
        - containerPort: 8080
          name: disappearing-act
          protocol: TCP

transformers.yaml

---
apiVersion: builtin
kind: PatchTransformer
metadata:
  name: test-transformer
patch: |-
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: test-transformer
    labels:
      test-transformer: did-my-job
target:
  kind: Deployment
  name: test-deployment

Expected behavior

This is the behavior seen in v3.7.0. The two port entries have distinct names, reflecting their definitions in resources.yaml.

$ ./kustomize-v3.7.0 version
{Version:kustomize/v3.7.0 GitCommit:42d1f7b792a80af34828ec4c89af99e1043351a7 BuildDate:2020-07-04T19:15:46Z GoOs:linux GoArch:amd64}
$ ./kustomize-v3.7.0 build .
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    test-transformer: did-my-job
  name: test-deployment
spec:
  template:
    spec:
      containers:
      - image: test-image
        name: test-deployment
        ports:
        - containerPort: 8080
          name: take-over-the-world
          protocol: TCP
        - containerPort: 8080
          name: disappearing-act
          protocol: TCP
$

Actual behavior

This is the behavior seen in v3.8.0 and v3.8.1. The two port entries have matching names.

$ ./kustomize-v3.8.1 version
{Version:kustomize/v3.8.1 GitCommit:0b359d0ef0272e6545eda0e99aacd63aef99c4d0 BuildDate:2020-07-16T00:58:46Z GoOs:linux GoArch:amd64}
$ ./kustomize-v3.8.1 build .
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    test-transformer: did-my-job
  name: test-deployment
spec:
  template:
    spec:
      containers:
      - image: test-image
        name: test-deployment
        ports:
        - containerPort: 8080
          name: take-over-the-world
          protocol: TCP
        - containerPort: 8080
          name: take-over-the-world
          protocol: TCP
$