Greetings helm community,
I'm a bit puzzled about how values are effectively evaluated when a chart references, as its dependency, another chart.

Here's a practical example:

helm template chart/charts/loki-2.12.2.tgz --set securityContext=null

this generates:

securityContext: null

Now, if I create a chart having loki as dependency:

apiVersion: v2
name: aaa
description: aaa
type: application
version: 0.0.1
dependencies:
- name: loki
  version: 2.12.2
  repository: https://grafana.github.io/helm-charts

the helm template command

helm template ./chart/ --set loki.securityContext=null

returns:

        securityContext:
        fsGroup: 10001
        runAsGroup: 10001
        runAsNonRoot: true
        runAsUser: 10001

which are the default values stored into the loki helm chart.

At this stage I am no longer able to nullify the value of securityContext but I could customise the value of each the parameters as follows:

helm template ./chart/ --set loki.securityContext.fsGroup=1 --set loki.securityContext.runAsNonRoot=false

        securityContext:
        fsGroup: 1
        runAsGroup: 10001
        runAsNonRoot: false
        runAsUser: 10001

Can you please review and confirm if this is a bug?

Output of helm version:
version.BuildInfo{Version:"v3.7.0", GitCommit:"eeac83883cb4014fe60267ec6373570374ce770b", GitTreeState:"clean", GoVersion:"go1.16.8"}

Output of kubectl version:
N/A, this happens in local

Cloud Provider/Platform (AKS, GKE, Minikube etc.):
N/A, this happens in local