From cc4fa2bbc833f4a141e8140004f28df8d329c027 Mon Sep 17 00:00:00 2001
From: Wim Dumon <wim@emweb.be>
Date: Wed, 28 Apr 2021 17:47:58 +0200
Subject: [PATCH] Offer option to disable traversalLimitInWords

Use case: large trusted input data file, mapped in memory by
MappedByteBuffer, which is often re-queried so a sensible
limit cannot be set.
---
 runtime/src/main/java/org/capnproto/ReaderArena.java | 8 +++++---
 runtime/src/main/java/org/capnproto/Serialize.java   | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/runtime/src/main/java/org/capnproto/ReaderArena.java b/runtime/src/main/java/org/capnproto/ReaderArena.java
index 13c9c87..63d8aa2 100644
--- a/runtime/src/main/java/org/capnproto/ReaderArena.java
+++ b/runtime/src/main/java/org/capnproto/ReaderArena.java
@@ -45,11 +45,13 @@ public final class ReaderArena implements Arena {
     }
 
     @Override
-    public final void checkReadLimit(int numBytes) {
-        if (numBytes > limit) {
+    public final void checkReadLimit(int numWords) {
+        if (limit == -1) {
+            return;
+        } else if (numWords > limit) {
             throw new DecodeException("Read limit exceeded.");
         } else {
-            limit -= numBytes;
+            limit -= numWords;
         }
     }
 }
diff --git a/runtime/src/main/java/org/capnproto/Serialize.java b/runtime/src/main/java/org/capnproto/Serialize.java
index 7dbfac0..4d9aeaa 100644
--- a/runtime/src/main/java/org/capnproto/Serialize.java
+++ b/runtime/src/main/java/org/capnproto/Serialize.java
@@ -145,7 +145,7 @@ public final class Serialize {
         }
         bb.position(segmentBase + totalWords * Constants.BYTES_PER_WORD);
 
-        if (totalWords > options.traversalLimitInWords) {
+        if (options.traversalLimitInWords != -1 && totalWords > options.traversalLimitInWords) {
             throw new DecodeException("Message size exceeds traversal limit.");
         }