diff --git a/trunk/src/kernel/srs_kernel_stream.cpp b/trunk/src/kernel/srs_kernel_stream.cpp
index 9873ced63..cec9f3d9a 100755
--- a/trunk/src/kernel/srs_kernel_stream.cpp
+++ b/trunk/src/kernel/srs_kernel_stream.cpp
@@ -68,3 +68,8 @@ void SrsSimpleStream::append(const char* bytes, int size)
     
     data.insert(data.end(), bytes, bytes + size);
 }
+
+void SrsSimpleStream::append(SrsSimpleStream* src)
+{
+    append(src->bytes(), src->length());
+}
diff --git a/trunk/src/kernel/srs_kernel_stream.hpp b/trunk/src/kernel/srs_kernel_stream.hpp
index 699673076..67e57ccb5 100644
--- a/trunk/src/kernel/srs_kernel_stream.hpp
+++ b/trunk/src/kernel/srs_kernel_stream.hpp
@@ -63,6 +63,7 @@ public:
      * @remark assert size is positive.
      */
     virtual void append(const char* bytes, int size);
+    virtual void append(SrsSimpleStream* src);
 };
 
 #endif
diff --git a/trunk/src/utest/srs_utest_protostack.cpp b/trunk/src/utest/srs_utest_protostack.cpp
index 0f0b8021a..64a0ce711 100644
--- a/trunk/src/utest/srs_utest_protostack.cpp
+++ b/trunk/src/utest/srs_utest_protostack.cpp
@@ -418,7 +418,7 @@ VOID TEST(ProtoStackTest, OnDecodeMessages)
 {
     srs_error_t err;
 
-    vector<char> bytes;
+    SrsSimpleStream bytes;
 
     if (true) {
         MockBufferIO io;
@@ -428,7 +428,7 @@ VOID TEST(ProtoStackTest, OnDecodeMessages)
         pkt->chunk_size = 0;
 
         HELPER_EXPECT_SUCCESS(p.send_and_free_packet(pkt, 1));
-        bytes.assign(io.out_buffer.bytes(), io.out_buffer.bytes() + io.out_buffer.length());
+        bytes.append(&io.out_buffer);
     }
 
     if (true) {
@@ -439,7 +439,7 @@ VOID TEST(ProtoStackTest, OnDecodeMessages)
         HELPER_EXPECT_SUCCESS(p.set_in_window_ack_size(1));
 
         SrsCommonMessage* msg;
-        io.in_buffer.append(bytes.data(), bytes.size());
+        io.in_buffer.append(&bytes);
         HELPER_EXPECT_FAILED(p.recv_message(&msg));
         srs_freep(msg);
     }
@@ -1225,3 +1225,43 @@ VOID TEST(ProtoStackTest, RecvMessage3)
     }
 }
 
+VOID TEST(ProtoStackTest, RecvMessage4)
+{
+    srs_error_t err;
+
+    if (true) {
+        MockBufferIO io;
+        SrsProtocol p(&io);
+
+        SrsSetChunkSizePacket* pkt = new SrsSetChunkSizePacket();
+        pkt->chunk_size = 256;
+        HELPER_EXPECT_SUCCESS(p.send_and_free_packet(pkt, 0));
+
+        io.in_buffer.append(&io.out_buffer);
+
+        SrsCommonMessage* msg;
+        SrsAutoFree(SrsCommonMessage, msg);
+        HELPER_EXPECT_SUCCESS(p.recv_message(&msg));
+
+        EXPECT_EQ(256, p.out_chunk_size);
+    }
+
+    if (true) {
+        MockBufferIO io;
+        SrsProtocol p(&io);
+
+        SrsUserControlPacket* pkt = new SrsUserControlPacket();
+        pkt->event_type = SrcPCUCSetBufferLength;
+        pkt->extra_data = 256;
+        HELPER_EXPECT_SUCCESS(p.send_and_free_packet(pkt, 0));
+
+        io.in_buffer.append(&io.out_buffer);
+
+        SrsCommonMessage* msg;
+        SrsAutoFree(SrsCommonMessage, msg);
+        HELPER_EXPECT_SUCCESS(p.recv_message(&msg));
+
+        EXPECT_EQ(256, p.in_buffer_length);
+    }
+}
+