A host accepts an explicitly-empty declaration (hq 127)

The empty-resources guard refused every empty body as a likely mistake,
with no way to say emptiness was meant — so the control plane could
never tell a node to drop its last resource. The envelope gains
owns_nothing: with it, an empty declaration is applied (the node drops
what the mesh owned); without it, empty is still refused, so a
truncated or mis-composed body cannot silently strip a machine. One
test, both directions.

internal/declaration/declaration_test.go

@@ -451,3 +451,16 @@ func TestAContainersResolverAndAddressAreAddressesOrRefused(t *testing.T) {
 		t.Errorf("a well-formed resolver and address were refused: %v", p)
 	}
 }
+
+func TestAnExplicitlyEmptyDeclarationIsAccepted(t *testing.T) {
+	// A deliberately-empty declaration (novox/hq issue 127) says owns_nothing, and is applied so
+	// the node drops what it last held — distinct from an accidental empty body, which is refused.
+	if _, err := Parse([]byte(`{"declaration":1,"owns_nothing":true,"resources":[]}`)); err != nil {
+		t.Fatalf("an explicitly-empty declaration must be accepted: %v", err)
+	}
+	// Without the marker, an empty declaration is still refused as a likely mistake.
+	_, err := Parse([]byte(`{"declaration":1,"resources":[]}`))
+	if err == nil || !strings.Contains(err.Error(), "no resources") {
+		t.Fatalf("an unmarked empty declaration must still be refused; got %v", err)
+	}
+}