From c6296c0bb168ca649ba5f03f64ff1c4f8a16a907 Mon Sep 17 00:00:00 2001
From: Katokoda <79760461+Katokoda@users.noreply.github.com>
Date: Fri, 5 Jun 2026 22:42:52 +0200
Subject: [PATCH] Fix/warship freezing no path (#4151)

**Add approved & assigned issue number here:**
Resolves #4113

## Description:

Warships now reject the PatrolTile change when the new one is a
different water component.
Adds a test ensuring this behavior.

## Please complete the following:

- [x] I have added screenshots for all UI updates
There are none
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
No texts
- [x] I have added relevant tests to the test directory
I also have tested in game and tested that the test does indeed fail if
my fix is not present.

## Please put your Discord username so you can be contacted if a bug or
regression is found:
Katokoda
---
 src/core/execution/MoveWarshipExecution.ts |  6 ++++
 tests/Warship.test.ts                      | 32 ++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/core/execution/MoveWarshipExecution.ts b/src/core/execution/MoveWarshipExecution.ts
index fb21d8858..f8bbc0560 100644
--- a/src/core/execution/MoveWarshipExecution.ts
+++ b/src/core/execution/MoveWarshipExecution.ts
@@ -13,6 +13,8 @@ export class MoveWarshipExecution implements Execution {
       console.warn(`MoveWarshipExecution: position ${this.position} not valid`);
       return;
     }
+    // Get water component of new TargetTile for connectivity check
+    const newPatrolTileWaterComponent = mg.getWaterComponent(this.position);
     // Cache warship list and build a lookup map — avoids repeated iteration
     const warshipMap = new Map(
       this.owner.units(UnitType.Warship).map((u) => [u.id(), u]),
@@ -28,6 +30,10 @@ export class MoveWarshipExecution implements Execution {
         console.warn(`MoveWarshipExecution: warship ${unitId} is not active`);
         continue;
       }
+      // Do not update the warship's patrolTile if it is in a different Water Component
+      if (!mg.hasWaterComponent(warship.tile(), newPatrolTileWaterComponent!)) {
+        continue;
+      }
       warship.updateWarshipState({
         patrolTile: this.position,
       });
diff --git a/tests/Warship.test.ts b/tests/Warship.test.ts
index 882084281..ea2dcd051 100644
--- a/tests/Warship.test.ts
+++ b/tests/Warship.test.ts
@@ -915,4 +915,36 @@ describe("Warship", () => {
     }
     expect(tradeShip.owner()).toBe(player1);
   });
+
+  test("Warship doesn't accept a new patrol tile if in a different water component", async () => {
+    const newPatrolTile = game.ref(coastX + 5, 15);
+
+    const warship = player1.buildUnit(
+      UnitType.Warship,
+      game.ref(coastX + 1, 10),
+      {
+        patrolTile: game.ref(coastX + 1, 10),
+      },
+    );
+
+    game.addExecution(new WarshipExecution(warship));
+
+    // Mock different water components
+    game.getWaterComponent = (tile: TileRef) => {
+      if (tile === newPatrolTile) return 1;
+      return 2;
+    };
+
+    game.hasWaterComponent = (tile: TileRef, component: number) => {
+      return game.getWaterComponent(tile) === component;
+    };
+
+    game.addExecution(
+      new MoveWarshipExecution(player1, [warship.id()], newPatrolTile),
+    );
+
+    executeTicks(game, 10);
+
+    expect(warship.warshipState().patrolTile).toBe(game.ref(coastX + 1, 10));
+  });
 });