From 7eaebf5abd644154a8edcfa9e0982e7fcdcebfdd Mon Sep 17 00:00:00 2001
From: usev6 <use_v6@aglaz.de>
Date: Sat, 9 Dec 2017 21:55:49 +0100
Subject: [PATCH] [jvm] Fix off-by-one in multi cache

---
 .../org/perl6/nqp/sixmodel/reprs/MultiCacheInstance.java     | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/vm/jvm/runtime/org/perl6/nqp/sixmodel/reprs/MultiCacheInstance.java b/src/vm/jvm/runtime/org/perl6/nqp/sixmodel/reprs/MultiCacheInstance.java
index 9fb504fded..46bc606b6a 100644
--- a/src/vm/jvm/runtime/org/perl6/nqp/sixmodel/reprs/MultiCacheInstance.java
+++ b/src/vm/jvm/runtime/org/perl6/nqp/sixmodel/reprs/MultiCacheInstance.java
@@ -96,9 +96,12 @@ public void add(CallCaptureInstance capture, SixModelObject result, ThreadContex
         if (numArgs >= MD_CACHE_MAX_ARITY)
             return;
 
+        /* The zero arity case was handled above.
+         * At index 0 we have the cache for arity 1 */
+        ArityCache ac = this.arityCaches[numArgs - 1];
+
         /* If the cache is saturated, don't do anything (we could instead do a random
          * replacement). */
-        ArityCache ac = this.arityCaches[numArgs];
         if (ac != null && ac.numEntries == MD_CACHE_MAX_ENTRIES)
             return;