1 files changed, 6 insertions, 5 deletions
diff --git a/source/portals.d b/source/portals.d
index 7bb5dc2..000e182 100644
--- a/source/portals.d
+++ b/source/portals.d
@@ -23,10 +23,13 @@ struct Portal {
 
     string toString(int[Portal* ] idMap)
     in {
-        assert(pair in idMap);
+        assert(pair == null || pair in idMap);
     }
     do {
-        return format!`%s, %s: %d`(y, x, idMap[pair]);
+        if (pair == null)
+            return format!`%s, %s: -1`(y, x);
+        else
+            return format!`%s, %s: %d`(y, x, idMap[pair]);
     }
 
     void fromString(string s, Portal[int] portalsById) {
@@ -42,9 +45,7 @@ struct Portal {
         s.formattedRead!"%d"(id);
         auto p = id in portalsById;
         if (p) {
-            p.pairWith(this); // this is a REALLY big bug. Portal() is
-            // being copied by value into the dict,
-            // so it's not using its final ref.
+            p.pairWith(this);
         }
 
     }