From c97290890e0c647a9ca04265d8d13ea305ff924d Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Tue, 17 Aug 2021 17:24:11 +0200
Subject: [PATCH] fixed push_deadstack in the root

---
 rulegen.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rulegen.cpp b/rulegen.cpp
index a1edfb76..3f5d52d0 100644
--- a/rulegen.cpp
+++ b/rulegen.cpp
@@ -1122,8 +1122,11 @@ void push_deadstack(vector<tsinfo>& hash, twalker w, tsinfo tsi, int dir) {
   hash.push_back(tsi);
 
   while(true) {
+    ufind(w);
+    if(isize(hash) > 10000) throw rulegen_failure("deadstack overflow");
     tsi.second += dir; w += dir;
     auto& ts = treestates[tsi.first];
+    if(ts.is_root) return;
     if(tsi.second == 0 || tsi.second == isize(ts.rules)) {
       w += wstep;
       tsi = get_tsinfo(w);