Cannot refer to some parameters from expression template

[nomeaning777]

Summary

What happened/what you expected to happen?

If PARAMETER-NAME is a prefix of another parameter, {{=inputs.parameters.PARAMETER-NAME}} will fail to resolve.
This is probably due to Expand function in util/expand/expand.go.

What version is it broken in?
v3.1.13

What version was it working in?
v3.1.12

Diagnostics

kind: Workflow
metadata:
  generateName: parameter-expand-
  annotations:
    workflows.argoproj.io/version: ">= 3.1.0"
spec:
  entrypoint: main
  templates:
    - name: main
      inputs:
        parameters:
          - name: a
            value: A
          - name: a2
            value: A2
      script:
        env:
          - name: A
            value: "{{=inputs.parameters.a}}"
          - name: A2
            value: "{{=inputs.parameters.a2}}"
        image: debian:9.4
        command: [bash]
        source: |
          echo "$A / $A2"

Workflow stdout of v3.1.13

{{=inputs.parameters.a}} / A2

Workflow stdout of v3.1.12

A / A2

What Kubernetes provider are you using? GKE v1.20

What executor are you running? Emissary

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[alexec]

This is the cause:

argo-workflows/util/expand/expand.go

Line 29 in 2fd4b8a

if strings.HasPrefix(keys[i+1]+".", k) {

This should probably be:

if strings.HasPrefix(keys[i+1], k+".") {

Should be easy to fix, would you like to submit a fix?