Results require runAfter when embedding Pipeline spec

[bobcatfish]

Expected Behavior

Embedding a Pipeline spec into a PipelineRun should not change the behaviour of results.

Actual Behavior

If you remove the runAfter clause from this example, you get an error caused by the controller mistakenly starting both Tasks simultaneously.

apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  generateName: test-case
  name: test-case-run
spec:
  params:
  - name: prefix
    value: prefix
  pipelineSpec:
    params:
    - name: prefix
    tasks:
    - name: generate-suffix
      taskSpec:
        results:
        - name: suffix
        steps:
        - name: generate-suffix
          image: alpine
          script: |
            echo -n "suffix" > $(results.suffix.path)
    - name: do-something
      taskSpec:
        params:
        - name: arg
        steps:
        - name: do-something
          image: alpine
          script: |
            echo "$(params.arg)"
      params:
      - name: arg
       # this should be enough to imply to the controller that this Task should run
       # after generate-suffix, but with runAfter removed, the controller starts it at
       # the same time as generate-suffix
        value: "$(params.prefix):$(tasks.generate-suffix.results.suffix)"

Steps to Reproduce the Problem

1. Apply the above yaml and look at the pipelinerun

Additional Info

Interestingly this doesnt happen when not embedding the pipelinespec, e.g. this other example does not have the same problem https://github.com/tektoncd/pipeline/blob/master/examples/v1beta1/pipelineruns/pipelinerun-results.yaml

• Tekton Pipeline version: HEAD @ 1346656

[bobcatfish]

Working on a fix for this now

/assign bobcatfish

[bobcatfish]

Fixed in #2471