Do not report tplink discovery failures as legacy connection failures (#124432)

* Do not report discovery failures as legacy connection failures

* Fix catching BaseException

homeassistant/components/tplink/config_flow.py

@@ -410,9 +410,18 @@ class TPLinkConfigFlow(ConfigFlow, domain=DOMAIN):
             self._discovered_device = await Discover.discover_single(
                 host, credentials=credentials
             )
-        except TimeoutError:
-            # Try connect() to legacy devices if discovery fails
-            self._discovered_device = await Device.connect(config=DeviceConfig(host))
+        except TimeoutError as ex:
+            # Try connect() to legacy devices if discovery fails. This is a
+            # fallback mechanism for legacy that can handle connections without
+            # discovery info but if it fails raise the original error which is
+            # applicable for newer devices.
+            try:
+                self._discovered_device = await Device.connect(
+                    config=DeviceConfig(host)
+                )
+            except Exception:  # noqa: BLE001
+                # Raise the original error instead of the fallback error
+                raise ex from ex
         else:
             if self._discovered_device.config.uses_http:
                 self._discovered_device.config.http_client = (

tests/components/tplink/test_config_flow.py

@@ -1289,6 +1289,33 @@ async def test_discovery_timeout_connect(
     assert mock_connect["connect"].call_count == 1
 
 
+async def test_discovery_timeout_connect_legacy_error(
+    hass: HomeAssistant,
+    mock_discovery: AsyncMock,
+    mock_connect: AsyncMock,
+    mock_init,
+) -> None:
+    """Test discovery tries legacy connect on timeout."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+    mock_discovery["discover_single"].side_effect = TimeoutError
+    mock_connect["connect"].side_effect = KasaException
+    await hass.async_block_till_done()
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "user"
+    assert not result["errors"]
+    assert mock_connect["connect"].call_count == 0
+
+    result2 = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_HOST: IP_ADDRESS}
+    )
+    await hass.async_block_till_done()
+    assert result2["type"] is FlowResultType.FORM
+    assert result2["errors"] == {"base": "cannot_connect"}
+    assert mock_connect["connect"].call_count == 1
+
+
 async def test_reauth_update_other_flows(
     hass: HomeAssistant,
     mock_discovery: AsyncMock,