action: simplify chart diff logic

We actually only care about the chart name or version changing, as we
assume proper (immutable) versioning by the publisher of the chart
(either the user, or the source-controller).

Signed-off-by: Hidde Beydals <hidde@hhh.computer>

internal/action/verify.go

@@ -38,7 +38,7 @@ var (
 	ErrReleaseNotObserved = errors.New("release not observed to be made for object")
 	ErrReleaseDigest      = errors.New("release digest verification error")
 	ErrChartChanged       = errors.New("release chart changed")
-	ErrConfigDigest       = errors.New("release config digest verification error")
+	ErrConfigDigest       = errors.New("release config values changed")
 )
 
 // ReleaseTargetChanged returns true if the given release and/or chart
@@ -157,10 +157,8 @@ func VerifyRelease(rls *helmrelease.Release, snapshot *v2.Snapshot, chrt *helmch
 		return ErrReleaseNotFound
 	}
 
-	if chrt != nil {
-		if _, eq := chartutil.DiffMeta(*rls.Chart.Metadata, *chrt); !eq {
-			return ErrChartChanged
-		}
+	if chrt != nil && (rls.Chart.Metadata.Name != chrt.Name || rls.Chart.Metadata.Version != chrt.Version) {
+		return ErrChartChanged
 	}
 
 	if snapshot == nil || !chartutil.VerifyValues(digest.Digest(snapshot.ConfigDigest), vals) {