From 96f52e05bf9f9cbf210bfe97007ddcd690e394ce Mon Sep 17 00:00:00 2001
From: Violeta Georgieva <milesg78@gmail.com>
Date: Fri, 14 Jul 2017 21:57:17 +0300
Subject: [PATCH] Fix #6969: Do not reset the states while streaming Json array

Motivation:

Calling JsonObjectDecoder#reset while streaming Json array over multiple
writes causes CorruptedFrameException to be thrown.

Modifications:

While streaming Json array and if the current readerIndex has been reset,
ensure that the states will not be reset.

Result:

Fixes #6969
---
 .../handler/codec/json/JsonObjectDecoder.java |  1 -
 .../codec/json/JsonObjectDecoderTest.java     | 34 +++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/codec/src/main/java/io/netty/handler/codec/json/JsonObjectDecoder.java b/codec/src/main/java/io/netty/handler/codec/json/JsonObjectDecoder.java
index cd5db99ff7..037c60c0af 100644
--- a/codec/src/main/java/io/netty/handler/codec/json/JsonObjectDecoder.java
+++ b/codec/src/main/java/io/netty/handler/codec/json/JsonObjectDecoder.java
@@ -92,7 +92,6 @@ public class JsonObjectDecoder extends ByteToMessageDecoder {
 
         if (this.idx > in.readerIndex() && lastReaderIndex != in.readerIndex()) {
             this.idx = in.readerIndex();
-            reset();
         }
 
         // index of next byte to process.
diff --git a/codec/src/test/java/io/netty/handler/codec/json/JsonObjectDecoderTest.java b/codec/src/test/java/io/netty/handler/codec/json/JsonObjectDecoderTest.java
index e1f28a5794..29175db3c7 100644
--- a/codec/src/test/java/io/netty/handler/codec/json/JsonObjectDecoderTest.java
+++ b/codec/src/test/java/io/netty/handler/codec/json/JsonObjectDecoderTest.java
@@ -71,6 +71,40 @@ public class JsonObjectDecoderTest {
         assertFalse(ch.finish());
     }
 
+    @Test
+    public void testStreamJsonArrayOverMultipleWrites() {
+        EmbeddedChannel ch = new EmbeddedChannel(new JsonObjectDecoder(true));
+
+        String arrayPart1 = "[{\"test";
+        String arrayPart2 = "case\"  : \"\\\"}]Escaped dou\\\"ble quotes \\\" in JSON str\\\"ing\"";
+        String arrayPart3 = "  }\n\n    , ";
+        String arrayPart4 = "{\"testcase\" : \"Streaming string me";
+        String arrayPart5 = "ssage\"} ]";
+
+        // Test array
+        boolean dataAvailable = ch.writeInbound(Unpooled.copiedBuffer("   " + arrayPart1, CharsetUtil.UTF_8));
+        assertFalse(dataAvailable);
+        dataAvailable = ch.writeInbound(Unpooled.copiedBuffer(arrayPart2, CharsetUtil.UTF_8));
+        assertFalse(dataAvailable);
+        dataAvailable = ch.writeInbound(Unpooled.copiedBuffer(arrayPart3, CharsetUtil.UTF_8));
+        assertTrue(dataAvailable);
+        dataAvailable = ch.writeInbound(Unpooled.copiedBuffer(arrayPart4, CharsetUtil.UTF_8));
+        assertTrue(dataAvailable);
+        dataAvailable = ch.writeInbound(Unpooled.copiedBuffer(arrayPart5 + "      ", CharsetUtil.UTF_8));
+        assertTrue(dataAvailable);
+
+        ByteBuf res = ch.readInbound();
+        assertEquals("{\"testcase\"  : \"\\\"}]Escaped dou\\\"ble quotes \\\" in JSON str\\\"ing\"  }",
+                res.toString(CharsetUtil.UTF_8));
+        res.release();
+
+        res = ch.readInbound();
+        assertEquals("{\"testcase\" : \"Streaming string message\"}", res.toString(CharsetUtil.UTF_8));
+        res.release();
+
+        assertFalse(ch.finish());
+    }
+
     @Test
     public void testSingleByteStream() {
         EmbeddedChannel ch = new EmbeddedChannel(new JsonObjectDecoder());