Template parallelism not limiting nested workflows

[WeiTang114]

Is this a BUG REPORT or FEATURE REQUEST?: BUG REPORT (or is it intended behavior?)

What happened:
Template parallelism is not limiting nested workflows when specified on the outer workflow.
I have a workflow template A. It has steps with withParam to run N times of workflow template B. B has steps with withParam to run several times of a container template one-step.
I set parallelism: 1 on A, and I expect to run only one B at a time.

What you expected to happen:
Only one B is run at a time.

How to reproduce it (as minimally and precisely as possible):
This is modified from parallelism-nested.yaml example.

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: seq-test-
spec:
  arguments:
    parameters:
    - name: seq-list
      value: |
        ["a","b","c","d"]
  entrypoint: A
  templates:
  - name: A
    parallelism: 1
    inputs:
      parameters:
      - name: seq-list
    steps:
    - - name: seq-step
        template: B
        arguments:
          parameters:
          - name: seq-id
            value: "{{item}}"
        withParam: "{{inputs.parameters.seq-list}}"

  - name: B
    inputs:
      parameters:
      - name: seq-id
    steps:
    - - name: jobs
        template: one-job
        arguments:
          parameters:
          - name: seq-id
            value: "{{inputs.parameters.seq-id}}"
        withParam: "[1, 2]"


  - name: one-job
    inputs:
      parameters:
      - name: seq-id
    container:
      image: alpine
      command: ['/bin/sh', '-c']
      args: ["echo {{inputs.parameters.seq-id}}; sleep 10"]

Anything else we need to know?:

Environment:

• Argo version:

argo: v2.2.0
  BuildDate: 2018-08-30T08:51:40Z
  GitCommit: af636ddd8455660f307d835814d3112b90815dfd
  GitTreeState: clean
  GitTag: v2.2.0
  GoVersion: go1.10.3
  Compiler: gc
  Platform: darwin/amd64

• Kubernetes version :

clientVersion:
  buildDate: 2018-09-10T11:44:26Z
  compiler: gc
  gitCommit: a4529464e4629c21224b3d52edfe0ea91b072862
  gitTreeState: clean
  gitVersion: v1.11.3
  goVersion: go1.11
  major: "1"
  minor: "11"
  platform: darwin/amd64
serverVersion:
  buildDate: 2018-09-13T22:19:55Z
  compiler: gc
  gitCommit: 8d9503f982872112eb283f78cefc6944af640427
  gitTreeState: clean
  gitVersion: v1.10.7-gke.2
  goVersion: go1.9.3b4
  major: "1"
  minor: 10+
  platform: linux/amd64

Other debugging information (if applicable):

• workflow result:

 $ argo get seq-test-bbm5v                                                                                                                                                                       [11:53:36]
Name:                seq-test-bbm5v
Namespace:           default
ServiceAccount:      default
Status:              Succeeded
Created:             Thu Oct 11 11:50:31 +0800 (3 minutes ago)
Started:             Thu Oct 11 11:50:31 +0800 (3 minutes ago)
Finished:            Thu Oct 11 11:51:00 +0800 (2 minutes ago)
Duration:            29 seconds
Parameters:
  seq-list:          ["a","b","c","d"]


STEP                  PODNAME                    DURATION  MESSAGE
 ✔ seq-test-bbm5v
 └-·-✔ seq-step(0:a)
   | └-·-✔ jobs(0:1)  seq-test-bbm5v-1283787062  12s
   |   └-✔ jobs(1:2)  seq-test-bbm5v-556325212   12s
   ├-✔ seq-step(1:b)
   | └-·-✔ jobs(0:1)  seq-test-bbm5v-2674682628  12s
   |   └-✔ jobs(1:2)  seq-test-bbm5v-2770338894  12s
   ├-✔ seq-step(2:c)
   | └-·-✔ jobs(0:1)  seq-test-bbm5v-554334974   13s
   |   └-✔ jobs(1:2)  seq-test-bbm5v-1762128036  13s
   └-✔ seq-step(3:d)
     └-·-✔ jobs(0:1)  seq-test-bbm5v-64729936    13s
       └-✔ jobs(1:2)  seq-test-bbm5v-3655250666  13s

[WeiTang114]

Fixed by #1046. Closing.