From a5097b937e8430eb4cdc8f64856520e8169cde54 Mon Sep 17 00:00:00 2001
From: Trustin Lee <t@motd.kr>
Date: Thu, 26 Jun 2014 18:53:50 +0900
Subject: [PATCH] Fix incorrect bytesBefore/indexOf() in ReplayingDecoderBuffer

Motivation:

bytesBefore(length, ...), bytesBefore(index, length, ...), and
indexOf(fromIndex, toIndex,...) in ReplayingDecoderBuffer are buggy.
They trigger 'REPLAY even when they don't need to.

Modification:

Implement the buggy methods properly so that REPLAYs are not triggered
unnecessarily.

Result:

Correct behvaior
---
 .../handler/codec/ReplayingDecoderBuffer.java | 36 ++++++++++++-------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/codec/src/main/java/io/netty/handler/codec/ReplayingDecoderBuffer.java b/codec/src/main/java/io/netty/handler/codec/ReplayingDecoderBuffer.java
index 108608dea5..4fa55cdf19 100644
--- a/codec/src/main/java/io/netty/handler/codec/ReplayingDecoderBuffer.java
+++ b/codec/src/main/java/io/netty/handler/codec/ReplayingDecoderBuffer.java
@@ -307,11 +307,15 @@ final class ReplayingDecoderBuffer extends ByteBuf {
 
     @Override
     public int indexOf(int fromIndex, int toIndex, byte value) {
-        int endIndex = buffer.indexOf(fromIndex, toIndex, value);
-        if (endIndex < 0) {
+        if (fromIndex == toIndex) {
+            return -1;
+        }
+
+        if (Math.max(fromIndex, toIndex) > buffer.writerIndex()) {
             throw REPLAY;
         }
-        return endIndex;
+
+        return buffer.indexOf(fromIndex, toIndex, value);
     }
 
     @Override
@@ -325,21 +329,27 @@ final class ReplayingDecoderBuffer extends ByteBuf {
 
     @Override
     public int bytesBefore(int length, byte value) {
-        checkReadableBytes(length);
-        int bytes = buffer.bytesBefore(length, value);
-        if (bytes < 0) {
-            throw REPLAY;
-        }
-        return bytes;
+        final int readerIndex = buffer.readerIndex();
+        return bytesBefore(readerIndex, buffer.writerIndex() - readerIndex, value);
     }
 
     @Override
     public int bytesBefore(int index, int length, byte value) {
-        int bytes = buffer.bytesBefore(index, length, value);
-        if (bytes < 0) {
+        final int writerIndex = buffer.writerIndex();
+        if (index >= writerIndex) {
             throw REPLAY;
         }
-        return bytes;
+
+        if (index <= writerIndex - length) {
+            return buffer.bytesBefore(index, length, value);
+        }
+
+        int res = buffer.bytesBefore(index, writerIndex - index, value);
+        if (res < 0) {
+            throw REPLAY;
+        } else {
+            return res;
+        }
     }
 
     @Override
@@ -359,7 +369,7 @@ final class ReplayingDecoderBuffer extends ByteBuf {
             throw REPLAY;
         }
 
-        if (index + length <= writerIndex) {
+        if (index <= writerIndex - length) {
             return buffer.forEachByte(index, length, processor);
         }