This **MAY** resolve the message in issue 312, but this fix ultimately breaks things and will need to eventually be rolled back.

QuestHelper/graph_core.lua

@@ -131,6 +131,9 @@ local prepared = false
   local linktime = 0
   
 function QH_Graph_Pathmultifind(st, nda, reverse, make_path)
+  QuestHelper: Assert(st.x and st.y and st.p)
+  if st.p == 26 then return nil end -- DENIED!!!!
+
   --QuestHelper:TextOut("Starting PMF")
   QuestHelper: Assert(not active)
   QuestHelper: Assert(prepared)
@@ -144,8 +147,6 @@ function QH_Graph_Pathmultifind(st, nda, reverse, make_path)
   
   --local stats = QuestHelper:CreateTable("graphcore --stats")
   
-  QuestHelper: Assert(st.x and st.y and st.p)
-  
   --stats.dests_complex = 0
   --stats.dests_total = 0
   

QuestHelper/routing_controller.lua

@@ -101,12 +101,16 @@ local function GetCachedPath(loc1, loc2)
     -- Not in either, time to create
     misses = misses + 1
     local nrt = QH_Graph_Pathfind(loc1.loc, loc2.loc, false, true)
+    if nrt then
       QuestHelper: Assert(nrt)
       if not pathcache_active[loc1] then pathcache_active[loc1] = new_pathcache_table() end
       if not pathcache_inactive[loc1] then pathcache_inactive[loc1] = new_pathcache_table() end
       pathcache_active[loc1][loc2] = nrt
       pathcache_inactive[loc1][loc2] = nrt
       return nrt
+    else
+      return nil
+    end
   else
     hits = hits + 1
     if not pathcache_active[loc1] then pathcache_active[loc1] = new_pathcache_table() end
@@ -134,6 +138,7 @@ local function ReplotPath(progress)
     
     if last_path[k + 1] then
       local nrt = GetCachedPath(last_path[k], last_path[k + 1])
+      if nrt then
         distance = distance + nrt.d
         QuestHelper: Assert(nrt)
       
@@ -180,6 +185,7 @@ local function ReplotPath(progress)
       
         if condense_class then condense_doit() end -- in case we have stuff left over
       end
+    end
     
     if progress then progress:SetPercentage(k / #last_path) end
   end
@@ -371,6 +377,7 @@ Route_Core_Init(
     
     rvv = QuestHelper:CreateTable("route controller path shunt returnvalue")
     local rv = QH_Graph_Pathmultifind(loc1.loc, lt, reverse, true)
+    if rv ~= nil then
       QuestHelper: Assert(#lt == #rv, string.format("lt has %d items, rt has %d items. Both should be the same.", #lt, #rv))
     
       -- We want to store the math.max(sqrt(#rv), 10) shortest paths
@@ -427,6 +434,9 @@ Route_Core_Init(
       QuestHelper:ReleaseTable(rv)  -- this had better be releasable
     
       return rvv
+    else
+      return nil
+    end
   end
 )
 

QuestHelper/routing_core.lua

@@ -773,6 +773,7 @@ function QH_Route_Core_Process()
           -- Refresh a subset of things.
           local forward = DistBatch(NodeList[idx], tlnod)
           local backward = DistBatch(NodeList[idx], tlnod, true)
+          if forward and backward then
           
             for k, v in ipairs(ActiveNodes) do
               Distance[idx][v] = forward[k]
@@ -785,6 +786,7 @@ function QH_Route_Core_Process()
             ctd = ctd + 1
             resynch_progress:SetPercentage(ctd / ct)
           end
+        end
         QuestHelper:ReleaseTable(tlnod)
       end
       QuestHelper:ReleaseTable(DistanceWaiting)
@@ -1124,6 +1126,7 @@ end
     
     local forward = DistBatch(NodeList[1], tlnod)
     
+    if forward then
       local ct = 1
       for _, v in ipairs(ActiveNodes) do
         if v ~= 1 then
@@ -1140,6 +1143,7 @@ end
       end
     
       QuestHelper:ReleaseTable(forward)
+    end
     QuestHelper:ReleaseTable(tlnod)
     
     Storage_Distance_StoreFromIDToAll(1)
@@ -1462,9 +1466,11 @@ function QH_Route_Core_DistanceClear(progress)
   for ani, idx in ipairs(ActiveNodes) do
     local forward = DistBatch(NodeList[idx], tlnod, false, true)
     
+    if forward then
       for k, v in ipairs(ActiveNodes) do
         Distance[idx][v] = forward[k]
       end
+    end
     
     if QuestHelper.loading_preroll and #ActiveNodes > 1 then QuestHelper.loading_preroll:SetPercentage(ani / #ActiveNodes) end