Merge branch 'fix/recents-wipe-jni-null-view'

Guard against Gio's null-view detach event (recents-wipe SIGABRT).

ble_android.go

@@ -225,6 +225,15 @@ func NewBLE() *BLE {
 //Enable
 func (b *BLE) Enable(view uintptr) {
 	log.Printf("ble.Enable()")
+	// view == 0 is Gio's detach signal (GioView.onDestroyView sends
+	// ViewEvent{View: 0} when the view is destroyed, e.g. the activity
+	// going away on a recents-wipe). Nothing to register; passing the null
+	// ref on would abort in JNI (GetObjectClass on null). A re-attach
+	// arrives as a fresh event with a live view. Callers that forward the
+	// event unfiltered are protected by this guard.
+	if view == 0 {
+		return
+	}
 	setJVM(app.JavaVM())
 	runInJVM(func(env *JNIEnv) {
 		log.Printf("ble.Enable(): inside runInJVM()")

jni_android.c

@@ -5,6 +5,14 @@
 
 void
 registerFragment(JNIEnv *env, jobject view) {
+	if (view == NULL) {
+		// Detach signal (Gio sends ViewEvent{View: 0} when the view is
+		// destroyed, e.g. the activity going away on a recents-wipe).
+		// The Go side already filters these; this guard keeps the JNI
+		// calls safe if one ever slips through (GetObjectClass on null
+		// aborts the process).
+		return;
+	}
 	jclass cls = (*env)->GetObjectClass(env, view);
 	jmethodID mid = (*env)->GetMethodID(env, cls, "getContext", "()Landroid/content/Context;");
 	jobject ctx = (*env)->CallObjectMethod(env, view, mid);