From 7d65fbd6e8e2c9e61a5aace4fc4b5062be26ca71 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 25 Nov 2023 14:55:38 +0000
Subject: [PATCH] Link graph: Fix incorrect job start/join dates when loading
 upstream saves

---
 src/saveload/linkgraph_sl.cpp | 35 ++---------------------------------
 src/sl/linkgraph_sl.cpp       | 11 ++++++++++-
 2 files changed, 12 insertions(+), 34 deletions(-)

diff --git a/src/saveload/linkgraph_sl.cpp b/src/saveload/linkgraph_sl.cpp
index 409606ee6c..adb4dad1be 100644
--- a/src/saveload/linkgraph_sl.cpp
+++ b/src/saveload/linkgraph_sl.cpp
@@ -201,39 +201,6 @@ SaveLoadTable GetLinkGraphScheduleDesc()
 	return schedule_desc;
 }
 
-/**
- * Spawn the threads for running link graph calculations.
- * Has to be done after loading as the cargo classes might have changed.
- */
-void AfterLoadLinkGraphs()
-{
-	if (IsSavegameVersionBefore(SLV_191)) {
-		for (LinkGraph *lg : LinkGraph::Iterate()) {
-			for (NodeID node_id = 0; node_id < lg->Size(); ++node_id) {
-				const Station *st = Station::GetIfValid((*lg)[node_id].Station());
-				if (st != nullptr) (*lg)[node_id].UpdateLocation(st->xy);
-			}
-		}
-
-		for (LinkGraphJob *lgj : LinkGraphJob::Iterate()) {
-			LinkGraph *lg = &(const_cast<LinkGraph &>(lgj->Graph()));
-			for (NodeID node_id = 0; node_id < lg->Size(); ++node_id) {
-				const Station *st = Station::GetIfValid((*lg)[node_id].Station());
-				if (st != nullptr) (*lg)[node_id].UpdateLocation(st->xy);
-			}
-		}
-	}
-	for (LinkGraphJob *lgj : LinkGraphJob::Iterate()) {
-		GetLinkGraphJobDayLengthScaleAfterLoad(lgj);
-	}
-
-	LinkGraphSchedule::instance.SpawnAll();
-
-	if (!_networking || _network_server) {
-		AfterLoad_LinkGraphPauseControl();
-	}
-}
-
 /**
  * All link graphs.
  */
@@ -286,6 +253,8 @@ struct LGRJChunkHandler : ChunkHandler {
 		while ((index = SlIterateArray()) != -1) {
 			LinkGraphJob *lgj = new (index) LinkGraphJob();
 			SlObject(lgj, slt);
+
+			GetLinkGraphJobDayLengthScaleAfterLoad(lgj);
 		}
 	}
 };
diff --git a/src/sl/linkgraph_sl.cpp b/src/sl/linkgraph_sl.cpp
index 082bf890d8..973c31c90e 100644
--- a/src/sl/linkgraph_sl.cpp
+++ b/src/sl/linkgraph_sl.cpp
@@ -41,7 +41,16 @@ void GetLinkGraphJobDayLengthScaleAfterLoad(LinkGraphJob *lgj)
 {
 	lgj->join_date_ticks *= DAY_TICKS;
 	lgj->join_date_ticks += LinkGraphSchedule::SPAWN_JOIN_TICK;
-	lgj->start_date_ticks = lgj->join_date_ticks - (lgj->Settings().recalc_time * DAY_TICKS);
+
+	uint recalc_scale;
+	if (IsSavegameVersionBefore(SLV_LINKGRAPH_SECONDS) && SlXvIsFeatureMissing(XSLFI_LINKGRAPH_DAY_SCALE, 3)) {
+		/* recalc time is in days */
+		recalc_scale = DAY_TICKS;
+	} else {
+		/* recalc time is in seconds */
+		recalc_scale = DAY_TICKS / SECONDS_PER_DAY;
+	}
+	lgj->start_date_ticks = lgj->join_date_ticks - (lgj->Settings().recalc_time * recalc_scale);
 }
 
 /**