--dependency-update is not working as expected

[JoniJnm]

helm upgrade --dependency-update is not updating the dependencies chart when the downloaded tgz version doesn't match with the chart.lock

I created a repository to reproduce the bug: https://github.com/JoniJnm/helm-bug

• The main branch needs the dependency mysql:9.12.3
• The v2 branch needs the dependency mysql:9.16.3

The steps:

$ cd /tmp
$ git clone https://github.com/JoniJnm/helm-bug
$ ls
Chart.lock  Chart.yaml  README.md
$ helm upgrade --install --dependency-update helm-bug .
Release "helm-bug" does not exist. Installing it now.
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈
Saving 1 charts
Downloading mysql from repo https://charts.bitnami.com/bitnami
Deleting outdated charts
NAME: helm-bug
LAST DEPLOYED: Tue Apr 23 18:42:47 2024
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

This downloads the mysql-9.12.3.tgz file:

$ ls charts/
mysql-9.12.3.tgz

But now, when the Chart.lock changes, it doesn't update the dependency:

$ git switch v2
$ helm upgrade --install --dependency-update helm-bug .
Release "helm-bug" has been upgraded. Happy Helming!
NAME: helm-bug
LAST DEPLOYED: Tue Apr 23 18:45:15 2024
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None

The dependency is not updated:

$ cat Chart.lock | grep version
  version: 9.16.3
$ ls charts/
mysql-9.12.3.tgz

$ helm version
version.BuildInfo{Version:"v3.14.4", GitCommit:"81c902a123462fd4052bc5e9aa9c513c4c8fc142", GitTreeState:"clean", GoVersion:"go1.21.9"}