From 04d5badb3ce4f0442d3f92dfdfe65a145cdf4b09 Mon Sep 17 00:00:00 2001
From: Hongze Cheng <hzcheng@taosdata.com>
Date: Tue, 4 Jan 2022 03:46:55 +0000
Subject: [PATCH] add forward compatilibity

---
 source/util/src/encode.c        |  3 +--
 source/util/test/encodeTest.cpp | 46 +++++++++++++++++++++------------
 2 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/source/util/src/encode.c b/source/util/src/encode.c
index 40c03ea051..096509d42a 100644
--- a/source/util/src/encode.c
+++ b/source/util/src/encode.c
@@ -127,15 +127,14 @@ void tEndDecode(SCoder* pCoder) {
   struct SCoderNode* pNode;
 
   ASSERT(pCoder->type == TD_DECODER);
-  ASSERT(tDecodeIsEnd(pCoder));
 
   pNode = TD_SLIST_HEAD(&(pCoder->stack));
   ASSERT(pNode);
   TD_SLIST_POP(&(pCoder->stack));
 
   pCoder->data = pNode->data;
+  pCoder->pos = pCoder->size + pNode->pos;
   pCoder->size = pNode->size;
-  pCoder->pos = pCoder->pos + pNode->pos;
 
   free(pNode);
 }
diff --git a/source/util/test/encodeTest.cpp b/source/util/test/encodeTest.cpp
index 1a861701d7..b178ee0b10 100644
--- a/source/util/test/encodeTest.cpp
+++ b/source/util/test/encodeTest.cpp
@@ -360,8 +360,8 @@ TEST(td_encode_test, compound_struct_encode_test) {
   SStructA_v2  sa2 = {.A_a = 10, .A_b = 65478, .A_c = "Hello", .A_d = 67, .A_e = 13};
   SFinalReq_v1 req1 = {.pA = &sa1, .v_a = 15, .v_b = 35};
   SFinalReq_v2 req2 = {.pA = &sa2, .v_a = 15, .v_b = 32, .v_c = 37};
-  SFinalReq_v1 dreq1;
-  SFinalReq_v2 dreq21, dreq22;
+  SFinalReq_v1 dreq11, dreq21;
+  SFinalReq_v2 dreq12, dreq22;
 
   // Get size
   tCoderInit(&encoder, TD_LITTLE_ENDIAN, nullptr, 0, TD_ENCODER);
@@ -386,27 +386,30 @@ TEST(td_encode_test, compound_struct_encode_test) {
   tCoderClear(&encoder);
 
   // Decode
+  // buf1 -> req1
   tCoderInit(&decoder, TD_LITTLE_ENDIAN, buf1, buf1size, TD_DECODER);
-  GTEST_ASSERT_EQ(tSFinalReq_v1_decode(&decoder, &dreq1), 0);
-  GTEST_ASSERT_EQ(dreq1.pA->A_a, req1.pA->A_a);
-  GTEST_ASSERT_EQ(dreq1.pA->A_b, req1.pA->A_b);
-  GTEST_ASSERT_EQ(strcmp(dreq1.pA->A_c, req1.pA->A_c), 0);
-  GTEST_ASSERT_EQ(dreq1.v_a, req1.v_a);
-  GTEST_ASSERT_EQ(dreq1.v_b, req1.v_b);
+  GTEST_ASSERT_EQ(tSFinalReq_v1_decode(&decoder, &dreq11), 0);
+  GTEST_ASSERT_EQ(dreq11.pA->A_a, req1.pA->A_a);
+  GTEST_ASSERT_EQ(dreq11.pA->A_b, req1.pA->A_b);
+  GTEST_ASSERT_EQ(strcmp(dreq11.pA->A_c, req1.pA->A_c), 0);
+  GTEST_ASSERT_EQ(dreq11.v_a, req1.v_a);
+  GTEST_ASSERT_EQ(dreq11.v_b, req1.v_b);
   tCoderClear(&decoder);
 
+  // buf1 -> req2 (backward compatibility)
   tCoderInit(&decoder, TD_LITTLE_ENDIAN, buf1, buf1size, TD_DECODER);
-  GTEST_ASSERT_EQ(tSFinalReq_v2_decode(&decoder, &dreq21), 0);
-  GTEST_ASSERT_EQ(dreq21.pA->A_a, req1.pA->A_a);
-  GTEST_ASSERT_EQ(dreq21.pA->A_b, req1.pA->A_b);
-  GTEST_ASSERT_EQ(strcmp(dreq21.pA->A_c, req1.pA->A_c), 0);
-  GTEST_ASSERT_EQ(dreq21.pA->A_d, 0);
-  GTEST_ASSERT_EQ(dreq21.pA->A_e, 0);
-  GTEST_ASSERT_EQ(dreq21.v_a, req1.v_a);
-  GTEST_ASSERT_EQ(dreq21.v_b, req1.v_b);
-  GTEST_ASSERT_EQ(dreq21.v_c, 0);
+  GTEST_ASSERT_EQ(tSFinalReq_v2_decode(&decoder, &dreq12), 0);
+  GTEST_ASSERT_EQ(dreq12.pA->A_a, req1.pA->A_a);
+  GTEST_ASSERT_EQ(dreq12.pA->A_b, req1.pA->A_b);
+  GTEST_ASSERT_EQ(strcmp(dreq12.pA->A_c, req1.pA->A_c), 0);
+  GTEST_ASSERT_EQ(dreq12.pA->A_d, 0);
+  GTEST_ASSERT_EQ(dreq12.pA->A_e, 0);
+  GTEST_ASSERT_EQ(dreq12.v_a, req1.v_a);
+  GTEST_ASSERT_EQ(dreq12.v_b, req1.v_b);
+  GTEST_ASSERT_EQ(dreq12.v_c, 0);
   tCoderClear(&decoder);
 
+  // buf2 -> req2
   tCoderInit(&decoder, TD_LITTLE_ENDIAN, buf2, buf2size, TD_DECODER);
   GTEST_ASSERT_EQ(tSFinalReq_v2_decode(&decoder, &dreq22), 0);
   GTEST_ASSERT_EQ(dreq22.pA->A_a, req2.pA->A_a);
@@ -418,4 +421,13 @@ TEST(td_encode_test, compound_struct_encode_test) {
   GTEST_ASSERT_EQ(dreq22.v_b, req2.v_b);
   GTEST_ASSERT_EQ(dreq22.v_c, req2.v_c);
   tCoderClear(&decoder);
+
+  tCoderInit(&decoder, TD_LITTLE_ENDIAN, buf2, buf2size, TD_DECODER);
+  GTEST_ASSERT_EQ(tSFinalReq_v1_decode(&decoder, &dreq21), 0);
+  GTEST_ASSERT_EQ(dreq21.pA->A_a, req2.pA->A_a);
+  GTEST_ASSERT_EQ(dreq21.pA->A_b, req2.pA->A_b);
+  GTEST_ASSERT_EQ(strcmp(dreq21.pA->A_c, req2.pA->A_c), 0);
+  GTEST_ASSERT_EQ(dreq21.v_a, req2.v_a);
+  GTEST_ASSERT_EQ(dreq21.v_b, req2.v_b);
+  tCoderClear(&decoder);
 }
\ No newline at end of file