Prevent crash

app/src/main/java/eu/faircode/email/EntityRule.java

@@ -236,11 +236,23 @@ public class EntityRule {
 
     private void onActionMove(Context context, EntityMessage message, JSONObject jargs) throws JSONException {
         long target = jargs.getLong("target");
+
+        DB db = DB.getInstance(context);
+        EntityFolder folder = db.folder().getFolder(target);
+        if (folder == null)
+            throw new IllegalArgumentException("Rule move to folder not found");
+
         EntityOperation.queue(context, message, EntityOperation.MOVE, target, false);
     }
 
     private void onActionCopy(Context context, EntityMessage message, JSONObject jargs) throws JSONException {
         long target = jargs.getLong("target");
+
+        DB db = DB.getInstance(context);
+        EntityFolder folder = db.folder().getFolder(target);
+        if (folder == null)
+            throw new IllegalArgumentException("Rule copy to folder not found");
+
         EntityOperation.queue(context, message, EntityOperation.COPY, target, false);
     }
 

app/src/main/java/eu/faircode/email/FragmentRule.java

@@ -837,15 +837,15 @@ public class FragmentRule extends FragmentBase {
                 case EntityRule.TYPE_MOVE:
                 case EntityRule.TYPE_COPY:
                     EntityFolder target = (EntityFolder) spTarget.getSelectedItem();
-                    jaction.put("target", target.id);
+                    jaction.put("target", target == null ? -1 : target.id);
                     break;
 
                 case EntityRule.TYPE_ANSWER:
                     EntityIdentity identity = (EntityIdentity) spIdent.getSelectedItem();
                     EntityAnswer answer = (EntityAnswer) spAnswer.getSelectedItem();
                     boolean cc = cbCc.isChecked();
-                    jaction.put("identity", identity.id);
-                    jaction.put("answer", answer.id);
+                    jaction.put("identity", identity == null ? -1 : identity.id);
+                    jaction.put("answer", answer == null ? -1 : answer.id);
                     jaction.put("cc", cc);
                     break;
             }