From 42978602ce52c9e40426fada59d33b001c95819e Mon Sep 17 00:00:00 2001
From: minoneer <minoneer@gmail.com>
Date: Sat, 15 Aug 2026 15:30:32 +0200
Subject: [PATCH] Fix IndexOutOfBoundsException in
 AlternativeCommandsHandler.getAlternative

getAlternative prunes collected WeakReferences through its own iterator, which
can remove every entry in a bucket. The following commands.get(0) then throws
IndexOutOfBoundsException.

Store the first live alias during the iteration and return that instead, or null
when nothing live remains - which the caller already treats as "no alternative".

Fixes #6608
---
 .../essentials/AlternativeCommandsHandler.java         | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Essentials/src/main/java/com/earth2me/essentials/AlternativeCommandsHandler.java b/Essentials/src/main/java/com/earth2me/essentials/AlternativeCommandsHandler.java
index 01f7fa3caf0..34319041020 100644
--- a/Essentials/src/main/java/com/earth2me/essentials/AlternativeCommandsHandler.java
+++ b/Essentials/src/main/java/com/earth2me/essentials/AlternativeCommandsHandler.java
@@ -116,6 +116,8 @@ public Command getAlternative(final String label) {
         }
 
         // return the first command that is not an alias
+        Command firstAlias = null;
+
         final Iterator<WeakReference<Command>> iterator = commands.iterator();
         while (iterator.hasNext()) {
             final Command cmd = iterator.next().get();
@@ -127,10 +129,14 @@ public Command getAlternative(final String label) {
             if (cmd.getName().equalsIgnoreCase(label)) {
                 return cmd;
             }
+
+            if (firstAlias == null) {
+                firstAlias = cmd;
+            }
         }
 
-        // return the first alias
-        return commands.get(0).get();
+        // return the first alias, or null if every reference in this bucket has been collected
+        return firstAlias;
     }
 
     public void executed(final String label, final Command pc) {