Persist an empty LLM API selection in OpenAI Conversation (#179893)

Co-authored-by: Claude <noreply@anthropic.com>

homeassistant/components/openai_conversation/config_flow.py

@@ -309,7 +309,7 @@ class OpenAISubentryFlowHandler(ConfigSubentryFlow):
         ] = bool
 
         if user_input is not None:
-            if not user_input.get(CONF_LLM_HASS_API):
+            if user_input.get(CONF_LLM_HASS_API) is None:
                 user_input.pop(CONF_LLM_HASS_API, None)
 
             if user_input[CONF_RECOMMENDED]:

tests/components/openai_conversation/test_config_flow.py

@@ -647,6 +647,25 @@ async def test_form_invalid_auth(hass: HomeAssistant, side_effect, error) -> Non
 @pytest.mark.parametrize(
     ("current_options", "new_options", "expected_options"),
     [
+        (  # Test clearing every llm api is stored as an empty list
+            {
+                CONF_RECOMMENDED: True,
+                CONF_LLM_HASS_API: ["assist"],
+                CONF_PROMPT: "",
+            },
+            (
+                {
+                    CONF_RECOMMENDED: True,
+                    CONF_LLM_HASS_API: [],
+                    CONF_PROMPT: "",
+                },
+            ),
+            {
+                CONF_RECOMMENDED: True,
+                CONF_LLM_HASS_API: [],
+                CONF_PROMPT: "",
+            },
+        ),
         (  # Test converting single llm api format to list
             {
                 CONF_RECOMMENDED: True,