EscapistsReintroduced/docs/evidence/radio-transfer-cancellation-2026-10-02/radio-proposal/fix.patch

--- a/addons/core/Scripts/Game/ERR/10_AI/ERR_HQNetwork.c
+++ b/addons/core/Scripts/Game/ERR/10_AI/ERR_HQNetwork.c
@@ -85,10 +85,8 @@
 		int target = Cursor + 1;
 		if (Sending)
 		{
-			if (now < Due)
-				return 0;
-   // A transmission takes two seconds. The sender must keep its physical
-   // radio throughout that interval, including the final manpack-to-HQ leg.
+   // A transmission takes two seconds. Validate both endpoints on every
+   // observed tick; only delivery logging and cursor advancement wait for Due.
    if (Cursor >= 0 && !Nodes[Cursor].Valid(!Downlink && Cursor == Nodes.Count() - 1))
     return Fail(journal, "transmitting carrier lost radio during transmission");
 			if (target < Nodes.Count())
@@ -97,6 +95,11 @@
 					return Fail(journal, "receiving carrier lost radio, died or changed ownership");
 				if (Cursor >= 0 && vector.DistanceXZ(SentFrom, Nodes[target].Carrier.GetOrigin()) > 500)
 					return Fail(journal, "receiver moved beyond the 500m link");
+			}
+			if (now < Due)
+				return 0;
+			if (target < Nodes.Count())
+			{
 				journal.Write("RECEIVE", Nodes[target].Label() + " received from " + SenderLabel(), MessageId);
 			}
 			else
--- a/tests/hq_network_regression.py
+++ b/tests/hq_network_regression.py
@@ -89,6 +89,64 @@
  assert(down->Advance(2000,&journal)==0);assert(down->Advance(4000,&journal)==0);assert(down->Advance(6000,&journal)==1);
  assert(!down->Originated&&down->OriginDue==-1);for(int j=beforeDown;j<journal.events.Count();j++)assert(journal.events[j].find("CALL")!=0);
  auto captured=network.Route(&c[2],true);captured->Advance(0,&journal);c[0].captured=true;assert(captured->Advance(2000,&journal)==-1);c[0].captured=false;
+ // The sender must stay valid on EVERY observed tick of the two-second hop,
+ // not only at completion. Recovery before Due cannot revive an interrupted hop.
+ for(bool downlink:{false,true})for(int reason=0;reason<3;reason++){
+  auto interrupted=network.Route(downlink?&c[1]:&c[0],downlink);ERR_HQJournal log;
+  assert(interrupted->Advance(0,&log)==0);
+  float sendingAt=3000;
+  if(downlink)sendingAt=2000;
+  assert(interrupted->Advance(sendingAt,&log)==0&&interrupted->Sending);
+  if(reason==0)c[0].alive=false;
+  if(reason==1)c[0].captured=true;
+  if(reason==2)c[0].radio=0;
+  assert(interrupted->Advance(sendingAt+1000,&log)==-1);
+  assert(interrupted->Failed&&log.events.back().find("LOST ")==0);
+  int terminalEvents=log.events.Count();
+  c[0].alive=true;c[0].captured=false;c[0].radio=2;
+  assert(interrupted->Advance(sendingAt+2000,&log)==-1&&log.events.Count()==terminalEvents);
+ }
+ // Receiver interruption and leaving/re-entering the link also cancel the
+ // same physical short-range hop in either direction, before its due time.
+ for(bool downlink:{false,true})for(int reason=0;reason<4;reason++){
+  auto interrupted=network.Route(downlink?&c[1]:&c[2],downlink);ERR_HQJournal log;
+  assert(interrupted->Advance(0,&log)==0);
+  float sendingAt=downlink?2000:3000;
+  assert(interrupted->Advance(sendingAt,&log)==0&&interrupted->Sending);
+  assert(interrupted->Nodes[interrupted->Cursor+1]->Carrier==&c[1]);
+  if(reason==0)c[1].alive=false;
+  if(reason==1)c[1].captured=true;
+  if(reason==2)c[1].radio=0;
+  if(reason==3)c[1].pos=V(3000);
+  assert(interrupted->Advance(sendingAt+1000,&log)==-1);
+  int terminalEvents=log.events.Count();
+  c[1].alive=true;c[1].captured=false;c[1].radio=1;c[1].pos=V(500);
+  assert(interrupted->Advance(sendingAt+2000,&log)==-1&&log.events.Count()==terminalEvents);
+ }
+ // HQ's first downlink leg has no physical sender; its original receiving
+ // manpack must still survive while waiting, rather than use a late recovery.
+ auto firstDown=network.Route(&c[1],true);ERR_HQJournal firstDownLog;
+ assert(firstDown->Advance(0,&firstDownLog)==0&&firstDown->Cursor==-1);
+ c[0].radio=1;assert(firstDown->Advance(1000,&firstDownLog)==-1);
+ c[0].radio=2;assert(firstDown->Advance(2000,&firstDownLog)==-1);
+ // Healthy receiver-bearing hops keep the cursor and RECEIVE log unchanged
+ // during intermediate polling, with both 500m boundary links still valid.
+ for(bool downlink:{false,true}){
+  auto healthy=network.Route(downlink?&c[1]:&c[2],downlink);ERR_HQJournal log;
+  assert(healthy->Advance(0,&log)==0);
+  float sendingAt=downlink?2000:3000;
+  assert(healthy->Advance(sendingAt,&log)==0&&healthy->Sending);
+  int cursor=healthy->Cursor,events=log.events.Count();
+  assert(healthy->Advance(sendingAt+1000,&log)==0&&healthy->Cursor==cursor&&log.events.Count()==events);
+  assert(healthy->Advance(sendingAt+2000,&log)==(downlink?1:0)&&healthy->Cursor==cursor+1);
+ }
+ // Healthy intermediate polling does not transmit early or duplicate log entries.
+ auto waiting=network.Route(&c[0]);ERR_HQJournal waitingLog;
+ assert(waiting->Advance(0,&waitingLog)==0&&waiting->Advance(3000,&waitingLog)==0);
+ int transmittingEvents=waitingLog.events.Count();
+ assert(waiting->Advance(4000,&waitingLog)==0&&waiting->Sending);
+ assert(waitingLog.events.Count()==transmittingEvents);
+ assert(waiting->Advance(5000,&waitingLog)==1&&waitingLog.events.Count()==transmittingEvents+1);
  auto timeout=network.Route(&c[2]);timeout->Advance(0,&journal);assert(timeout->Advance(30001,&journal)==-1);
  Network disconnected;disconnected.Add(&c[1],&group,1,1);disconnected.Build();assert(!disconnected.Route(&c[1]));
  Network boundary;c[1].pos=V(501);boundary.Add(&c[0],&group,1,2);boundary.Add(&c[1],&group,2,1);boundary.Build();assert(!boundary.Route(&c[1]));