iceberg: simplify namespace properties normalization

weed/s3api/iceberg/iceberg.go

@@ -402,15 +402,10 @@ func parsePagination(r *http.Request) (pageToken string, pageSize int, err error
 }
 
 func normalizeNamespaceProperties(properties map[string]string) map[string]string {
-	if len(properties) == 0 {
+	if properties == nil {
 		return map[string]string{}
 	}
-
-	normalized := make(map[string]string, len(properties))
-	for k, v := range properties {
-		normalized[k] = v
-	}
-	return normalized
+	return properties
 }
 
 // handleConfig returns catalog configuration.

weed/s3api/iceberg/iceberg_namespace_properties_test.go

@@ -12,7 +12,7 @@ func TestNormalizeNamespacePropertiesNil(t *testing.T) {
 	}
 }
 
-func TestNormalizeNamespacePropertiesClonesInput(t *testing.T) {
+func TestNormalizeNamespacePropertiesReturnsInputWhenSet(t *testing.T) {
 	input := map[string]string{
 		"owner": "analytics",
 	}
@@ -22,8 +22,8 @@ func TestNormalizeNamespacePropertiesClonesInput(t *testing.T) {
 		t.Fatalf("normalized properties value = %q, want %q", properties["owner"], "analytics")
 	}
 
-	input["owner"] = "mutated"
-	if properties["owner"] != "analytics" {
-		t.Fatalf("normalized properties was mutated via input map")
+	input["owner"] = "updated"
+	if properties["owner"] != "updated" {
+		t.Fatalf("normalizeNamespaceProperties should reuse the input map when non-nil")
 	}
 }