test(octopus): pin that the auto-wiring guard tests for content, not presence

automatic_config() records the device set it wired on every call,
including calls that wired nothing, so the recorded set is [] rather
than None after one run on an account with no devices. The "have we
ever wired anything" guard therefore has to test that set for content:
an `is not None` check passes from the second call onwards and blanks a
manual apps.yaml config that auto-discovery never touched.

The existing single-call test could not catch that, so add one that runs
automatic_config() repeatedly with no devices. Corrects the comment,
which described the guard as an is-not-None check it never was.

Author: springfall2008

apps/predbat/octopus.py

@@ -1175,9 +1175,11 @@ def automatic_config(self, tariffs):
                 self.set_arg("metric_standing_charge", self.get_entity_name("sensor", tariff + "_standing"))
         devices = self.get_intelligent_devices()
         # Also enter this block when the device set has emptied, so the slot args are cleared rather
-        # than left pointing at a device that no longer exists. Only once something has been wired
-        # though (intelligent_config_devices is not None): before the first discovery a user's own
-        # apps.yaml entries are the only wiring there is, and blanking them would break a manual setup.
+        # than left pointing at a device that no longer exists. Only once real devices have actually
+        # been wired though - hence the truthiness test rather than an `is not None` one. The set
+        # below is recorded on every call, including calls that wired nothing, so it is [] and not
+        # None after the first run on an account with no devices; treating that as "previously
+        # wired" would blank a user's own apps.yaml entries, which auto-discovery never touched.
         if devices or self.intelligent_config_devices:
             # Suspended devices (e.g. an old/decommissioned charger still linked to the Octopus
             # account) aren't actively charging, so exclude them from the entity lists and from

apps/predbat/tests/test_octopus_misc.py

@@ -2053,6 +2053,7 @@ def test_octopus_automatic_config_clears_removed_devices(my_predbat):
     Tests:
     - Test 1: Slot args are cleared when the last discovered device disappears
     - Test 2: Manually configured slot args are untouched when no device was ever discovered
+    - Test 3: Manually configured slot args survive repeated runs with no devices
     """
     print("\n**** Running Octopus automatic_config device removal tests ****")
     failed = False
@@ -2093,6 +2094,26 @@ def test_octopus_automatic_config_clears_removed_devices(my_predbat):
     else:
         print("PASS: Manual slot config untouched when no device was ever discovered")
 
+    # Test 3: automatic_config() records the device set it wired on every call, including the calls
+    # where it wired nothing - so after one run with no devices the recorded set is [] rather than
+    # None. The "have we ever wired anything" guard therefore has to test that set for content, not
+    # merely for being set: an `is not None` check would pass here from the second call onwards and
+    # blank a manual apps.yaml config that auto-discovery never touched.
+    print("\n*** Test 3: Manual slot config survives repeated runs with no devices ***")
+    my_predbat.args["octopus_intelligent_slot"] = "binary_sensor.manually_configured_dispatching"
+    api3 = OctopusAPI(my_predbat, key="test-api-key", account_id="test-account", automatic=False)
+    api3.intelligent_devices = {}
+
+    api3.automatic_config(["import"])
+    api3.automatic_config(["import"])
+    api3.automatic_config(["import"])
+
+    if my_predbat.args.get("octopus_intelligent_slot") != "binary_sensor.manually_configured_dispatching":
+        print(f"ERROR: Repeated runs with no devices blanked the manual slot config, got {my_predbat.args.get('octopus_intelligent_slot')}")
+        failed = True
+    else:
+        print("PASS: Manual slot config survives repeated runs with no devices")
+
     my_predbat.args.clear()
     my_predbat.args.update(original_args)