From 0e6061455f2adc18ca5c29bb8997292e60ffdeb2 Mon Sep 17 00:00:00 2001
From: tastybento <tastybento@wasteofplastic.com>
Date: Sun, 24 Nov 2019 13:45:18 -0800
Subject: [PATCH] Fixes flow  into adjacent islands when island abut.

https://github.com/BentoBoxWorld/BentoBox/issues/1034
---
 .../LiquidsFlowingOutListener.java            | 12 ++++++++---
 .../LiquidsFlowingOutListenerTest.java        | 21 ++++++++++++++++++-
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/main/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListener.java b/src/main/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListener.java
index d12406164..9cb5b6e3a 100644
--- a/src/main/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListener.java
+++ b/src/main/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListener.java
@@ -1,11 +1,14 @@
 package world.bentobox.bentobox.listeners.flags.worldsettings;
 
+import java.util.Optional;
+
 import org.bukkit.block.Block;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.block.BlockFromToEvent;
 
 import world.bentobox.bentobox.api.flags.FlagListener;
+import world.bentobox.bentobox.database.objects.Island;
 import world.bentobox.bentobox.lists.Flags;
 
 /**
@@ -15,10 +18,11 @@ import world.bentobox.bentobox.lists.Flags;
  */
 public class LiquidsFlowingOutListener extends FlagListener {
 
-    @EventHandler(priority = EventPriority.LOWEST)
+    @EventHandler(priority = EventPriority.LOWEST, ignoreCancelled = true)
     public void onLiquidFlow(BlockFromToEvent e) {
         Block from = e.getBlock();
         Block to = e.getToBlock();
+
         if (!getIWM().inWorld(from.getLocation()) || Flags.LIQUIDS_FLOWING_OUT.isSetForWorld(from.getWorld())) {
             // We do not want to run any check if this is not the right world or if it is allowed.
             return;
@@ -31,8 +35,10 @@ public class LiquidsFlowingOutListener extends FlagListener {
             return;
         }
 
-        // Only prevent if it is flowing into the area between islands.
-        if (!getIslands().getProtectedIslandAt(to.getLocation()).isPresent()) {
+        // Only prevent if it is flowing into the area between islands or into another island.
+        Optional<Island> fromIsland = getIslands().getProtectedIslandAt(from.getLocation());
+        Optional<Island> toIsland = getIslands().getProtectedIslandAt(to.getLocation());
+        if (!toIsland.isPresent() || (fromIsland.isPresent() && !fromIsland.equals(toIsland))) {
             e.setCancelled(true);
         }
     }
diff --git a/src/test/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListenerTest.java b/src/test/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListenerTest.java
index cc556e977..bb388b5b4 100644
--- a/src/test/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListenerTest.java
+++ b/src/test/java/world/bentobox/bentobox/listeners/flags/worldsettings/LiquidsFlowingOutListenerTest.java
@@ -2,7 +2,8 @@ package world.bentobox.bentobox.listeners.flags.worldsettings;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.Matchers.any;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -160,6 +161,24 @@ public class LiquidsFlowingOutListenerTest {
         assertFalse(event.isCancelled());
     }
 
+    /**
+     * Asserts that the event is cancelled when liquid flows from one island's protection range into different island's range,
+     * e.g., when islands abut.
+     * Test for {@link LiquidsFlowingOutListener#onLiquidFlow(BlockFromToEvent)}
+     */
+    @Test
+    public void testLiquidFlowsToAdjacentIsland() {
+        // There's a protected island at the "to"
+        Island island = mock(Island.class);
+        when(islandsManager.getProtectedIslandAt(eq(to.getLocation()))).thenReturn(Optional.of(island));
+        // There is another island at the "from"
+        Island fromIsland = mock(Island.class);
+        when(islandsManager.getProtectedIslandAt(eq(from.getLocation()))).thenReturn(Optional.of(fromIsland));
+        // Run
+        new LiquidsFlowingOutListener().onLiquidFlow(event);
+        assertTrue(event.isCancelled());
+    }
+
     /**
      * Asserts that the event is cancelled with the default configuration provided in {@link LiquidsFlowingOutListenerTest#setUp()}.
      */