Fix ESPHome unnecessary probing on DHCP discovery (#149713)

homeassistant/components/esphome/config_flow.py

@@ -316,10 +316,11 @@ class EsphomeFlowHandler(ConfigFlow, domain=DOMAIN):
             # Don't call _fetch_device_info() for ignored entries
             raise AbortFlow("already_configured")
         configured_host: str | None = entry.data.get(CONF_HOST)
-        configured_port: int | None = entry.data.get(CONF_PORT)
-        if configured_host == host and configured_port == port:
+        configured_port: int = entry.data.get(CONF_PORT, DEFAULT_PORT)
+        # When port is None (from DHCP discovery), only compare hosts
+        if configured_host == host and (port is None or configured_port == port):
             # Don't probe to verify the mac is correct since
-            # the host and port matches.
+            # the host matches (and port matches if provided).
             raise AbortFlow("already_configured")
         configured_psk: str | None = entry.data.get(CONF_NOISE_PSK)
         await self._fetch_device_info(host, port or configured_port, configured_psk)

tests/components/esphome/test_config_flow.py

@@ -2485,3 +2485,36 @@ async def test_reconfig_name_conflict_overwrite(
         )
         is None
     )
+
+
+@pytest.mark.usefixtures("mock_setup_entry")
+async def test_discovery_dhcp_no_probe_same_host_port_none(
+    hass: HomeAssistant, mock_client: APIClient
+) -> None:
+    """Test dhcp discovery does not probe when host matches and port is None."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        data={CONF_HOST: "192.168.43.183", CONF_PORT: 6053, CONF_PASSWORD: ""},
+        unique_id="11:22:33:44:55:aa",
+    )
+    entry.add_to_hass(hass)
+
+    # DHCP discovery with same MAC and host (WiFi device)
+    service_info = DhcpServiceInfo(
+        ip="192.168.43.183",
+        hostname="test8266",
+        macaddress="11:22:33:44:55:aa",  # Same MAC as configured
+    )
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_DHCP}, data=service_info
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"
+
+    # Verify device_info was NOT called (no probing)
+    mock_client.device_info.assert_not_called()
+
+    # Host should remain unchanged
+    assert entry.data[CONF_HOST] == "192.168.43.183"