test: Add test for applying STP setting even STP disabled

Ovirt use case requires nmstate to apply STP settings even STP been
disabled. Adding test for this use case as tier1.

Integration test case included.

Signed-off-by: Gris Ge <fge@redhat.com>

tests/integration/nm/linux_bridge_test.py

@@ -341,3 +341,59 @@ def test_partially_consume_linux_bridge_port(
             f"nmcli -g GENERAL.STATE d show {DUMMY1}".split(), check=True
         )[1]
     )
+
+
+@pytest.mark.tier1
+def test_linux_bridge_store_stp_setting_even_disabled(
+    eth1_up,
+):
+    with linux_bridge(
+        BRIDGE0,
+        bridge_subtree_state={
+            LB.PORT_SUBTREE: [
+                {
+                    LB.Port.NAME: "eth1",
+                }
+            ],
+            LB.OPTIONS_SUBTREE: {
+                LB.STP_SUBTREE: {
+                    LB.STP.ENABLED: False,
+                    LB.STP.FORWARD_DELAY: 16,
+                    LB.STP.HELLO_TIME: 2,
+                    LB.STP.MAX_AGE: 20,
+                    LB.STP.PRIORITY: 20480,
+                }
+            },
+        },
+    ) as state:
+        assertlib.assert_state_match(state)
+        assert (
+            exec_cmd(
+                f"nmcli -g bridge.stp c show {BRIDGE0}".split(),
+            )[1].strip()
+            == "no"
+        )
+        assert (
+            exec_cmd(
+                f"nmcli -g bridge.forward-delay c show {BRIDGE0}".split(),
+            )[1].strip()
+            == "16"
+        )
+        assert (
+            exec_cmd(
+                f"nmcli -g bridge.hello-time c show {BRIDGE0}".split(),
+            )[1].strip()
+            == "2"
+        )
+        assert (
+            exec_cmd(
+                f"nmcli -g bridge.max-age c show {BRIDGE0}".split(),
+            )[1].strip()
+            == "20"
+        )
+        assert (
+            exec_cmd(
+                f"nmcli -g bridge.priority c show {BRIDGE0}".split(),
+            )[1].strip()
+            == "20480"
+        )