Exclude content digests from Chart.lock metadata hash

HashReq now strips per-dependency digest fields so the top-level lock
digest continues to detect Chart.yaml drift independently of tarball bytes.

Signed-off-by: Simone Tollardo <simone.tollardo@redhat.com>

internal/resolver/resolver.go

@@ -209,9 +209,13 @@ func (r *Resolver) Resolve(reqs []*chart.Dependency, repoNames map[string]string
 // HashReq generates a hash of the dependencies.
 //
 // This should be used only to compare against another hash generated by this
-// function.
+// function. Per-dependency content digests are excluded; the top-level lock
+// digest tracks Chart.yaml constraints and resolved metadata only.
 func HashReq(req, lock []*chart.Dependency) (string, error) {
-	data, err := json.Marshal([2][]*chart.Dependency{req, lock})
+	data, err := json.Marshal([2][]*chart.Dependency{
+		dependenciesForMetadataHash(req),
+		dependenciesForMetadataHash(lock),
+	})
 	if err != nil {
 		return "", err
 	}
@@ -219,6 +223,23 @@ func HashReq(req, lock []*chart.Dependency) (string, error) {
 	return "sha256:" + s, err
 }
 
+// dependenciesForMetadataHash returns a copy of deps with content digests cleared.
+func dependenciesForMetadataHash(deps []*chart.Dependency) []*chart.Dependency {
+	if len(deps) == 0 {
+		return nil
+	}
+	out := make([]*chart.Dependency, len(deps))
+	for i, d := range deps {
+		if d == nil {
+			continue
+		}
+		cp := *d
+		cp.Digest = ""
+		out[i] = &cp
+	}
+	return out
+}
+
 // HashV2Req generates a hash of requirements generated in Helm v2.
 //
 // This should be used only to compare against another hash generated by the

internal/resolver/resolver_test.go

@@ -19,6 +19,9 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
 	chart "helm.sh/helm/v4/pkg/chart/v2"
 	"helm.sh/helm/v4/pkg/registry"
 )
@@ -308,3 +311,21 @@ func TestGetLocalPath(t *testing.T) {
 		})
 	}
 }
+
+func TestHashReqIgnoresContentDigest(t *testing.T) {
+	req := []*chart.Dependency{
+		{Name: "alpine", Version: "0.1.0", Repository: "http://localhost:8879/charts"},
+	}
+	lockWithout := []*chart.Dependency{
+		{Name: "alpine", Version: "0.1.0", Repository: "http://localhost:8879/charts"},
+	}
+	lockWith := []*chart.Dependency{
+		{Name: "alpine", Version: "0.1.0", Repository: "http://localhost:8879/charts", Digest: "sha256:abc123"},
+	}
+
+	h1, err := HashReq(req, lockWithout)
+	require.NoError(t, err)
+	h2, err := HashReq(req, lockWith)
+	require.NoError(t, err)
+	assert.Equal(t, h1, h2)
+}