From 711ae44605719a83b317e6c23808e91de8d93dfa Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Mon, 23 Aug 2021 15:50:08 +0200
Subject: [PATCH] rulegen:: handle dead roots

---
 rulegen.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/rulegen.cpp b/rulegen.cpp
index 389126ef..155911da 100644
--- a/rulegen.cpp
+++ b/rulegen.cpp
@@ -1536,6 +1536,15 @@ EX void rules_iteration() {
 
   branch_conflicts_seen.clear();
 
+  // handle dead roots -- some of their branches MUST live
+  for(int id=0; id<isize(treestates); id++) if(treestates[id].is_root && !treestates[id].is_live) {
+    auto r = treestates[id].rules;
+    for(int i=0; i<isize(r); i++) if(r[i] >= 0) {
+      examine_branch(id, i, i);
+      break;
+      }
+    }
+
   for(int id=0; id<isize(treestates); id++) if(treestates[id].is_live) {
     auto r = treestates[id].rules; /* no & because treestates might have moved */
     if(r.empty()) continue;