Fixed an issue causing a build up of pulses when regions are unloaded and npcs are still navigating back to their spawns

Server/src/main/core/game/node/entity/npc/NPC.java

@@ -462,7 +462,8 @@ public class NPC extends Entity {
 					getLocks().lockMovement(100);
 					getImpactHandler().setDisabledTicks(100);
 					setAttribute("return-to-spawn", true);
-					GameWorld.getPulser().submit(new MovementPulse(this, getProperties().getSpawnLocation(), Pathfinder.SMART) {
+
+					MovementPulse returnPulse = new MovementPulse(this, getProperties().getSpawnLocation(), Pathfinder.SMART) {
 						@Override
 						public boolean pulse() {
 							getProperties().getCombatPulse().stop();
@@ -470,9 +471,13 @@ public class NPC extends Entity {
 							fullRestore();
 							getImpactHandler().setDisabledTicks(0);
 							removeAttribute("return-to-spawn");
+							removeAttribute("return-to-spawn-pulse");
 							return true;
 						}
-					});
+					};
+
+					setAttribute("return-to-spawn-pulse", returnPulse);
+					GameWorld.getPulser().submit(returnPulse);
 					return;
 				}
 				if (dialoguePlayer == null || !dialoguePlayer.isActive() || !dialoguePlayer.getInterfaceManager().hasChatbox()) {
@@ -528,6 +533,14 @@ public class NPC extends Entity {
 		getWalkingQueue().reset();
 		getPulseManager().clear();
 		getUpdateMasks().reset();
+		if (getAttribute("return-to-spawn", false)) {
+			this.location = getProperties().getSpawnLocation();
+			MovementPulse returnPulse = getAttribute("return-to-spawn-pulse");
+			if (returnPulse != null) {
+				returnPulse.pulse();
+				returnPulse.stop();
+			}
+		}
 		Repository.removeRenderableNPC(this);
 		if (getViewport().getRegion() instanceof DynamicRegion) {
 			clear();

Server/src/test/kotlin/core/PathfinderTests.kt

@@ -16,6 +16,7 @@ import core.game.node.entity.impl.PulseType
 import core.game.node.entity.npc.NPC
 import core.game.node.entity.player.Player
 import core.game.world.GameWorld
+import core.game.world.map.Region
 import core.net.packet.PacketProcessor
 import core.plugin.ClassScanner
 import core.plugin.Plugin
@@ -221,4 +222,39 @@ class PathfinderTests {
             Assertions.assertEquals(1.0, p.location.getDistance(npc.location))
         }
     }
+
+    @Test fun npcShouldReliablyReturnToSpawnLocationIfTooFar() {
+        //spawn a player into the area just to make sure it ticks...
+        TestUtils.getMockPlayer("areatest").use { p ->
+            val npc = NPC(1, Location.create(3240, 3226, 0))
+            npc.isWalks = true
+            npc.isNeverWalks = false
+            npc.walkRadius = 5
+            npc.init()
+            npc.properties.spawnLocation = ServerConstants.HOME_LOCATION
+            TestUtils.advanceTicks(5, false)
+            Assertions.assertEquals(true, npc.getAttribute("return-to-spawn", false))
+            TestUtils.advanceTicks(50, false)
+            Assertions.assertEquals(true, npc.location.getDistance(ServerConstants.HOME_LOCATION) <= 9)
+        }
+    }
+
+    @Test fun npcShouldReliablyReturnToSpawnEvenIfRegionUnloaded() {
+        //spawn a player into the area just to make sure it ticks...
+        TestUtils.getMockPlayer("areaunloadtest").use { p ->
+            val npc = NPC(1, Location.create(3240, 3226, 0))
+            npc.isWalks = true
+            npc.isNeverWalks = false
+            npc.walkRadius = 5
+            npc.init()
+            npc.properties.spawnLocation = ServerConstants.HOME_LOCATION
+            TestUtils.advanceTicks(3, false)
+            Assertions.assertEquals(true, npc.getAttribute("return-to-spawn", false))
+            p.clear()
+            RegionManager.forId(npc.location.regionId).flagInactive(true)
+            TestUtils.advanceTicks(50, false)
+            Assertions.assertEquals(false, npc.getAttribute("return-to-spawn", false))
+            Assertions.assertEquals(true, npc.location.getDistance(ServerConstants.HOME_LOCATION) <= 5)
+        }
+    }
 }