[wifi] Keep a second fallback AP start from resetting the LN882x (#20168)

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -28,6 +28,11 @@ extern "C" {
 }
 #endif
 
+#ifdef USE_LN882X
+#include <WiFiPrivate.h>
+#undef DATA  // clashes with setup_priority::DATA
+#endif
+
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
@@ -770,6 +775,13 @@ bool WiFiComponent::wifi_start_ap_(const WiFiAP &ap) {
 
   yield();
 
+#ifdef USE_LN882X
+  // LibreTiny's LN882H softAP() points ap.bssid at a static array and frees it
+  // on the next call, tripping FreeRTOS's configASSERT until the watchdog
+  // resets the chip. Clear it so that a second AP start frees nothing.
+  static_cast<WiFiData *>(WiFi.data)->ap.bssid = nullptr;
+#endif
+
   return WiFi.softAP(ap.ssid_.c_str(), ap.password_.empty() ? NULL : ap.password_.c_str(),
                      ap.has_channel() ? ap.get_channel() : 1, ap.get_hidden());
 }

tests/components/wifi/test-ap.ln882x-ard.yaml

@@ -0,0 +1,9 @@
+wifi:
+  networks:
+    - ssid: MySSID
+      password: password1
+  ap:
+    ssid: Fallback Hotspot
+    password: password2
+
+captive_portal: