fix: create function bufSize default value 0

source/dnode/mnode/impl/src/mndFunc.c

@@ -314,7 +314,7 @@ static int32_t mndProcessCreateFuncReq(SNodeMsg *pReq) {
    goto _OVER;
  }
 
-  if (createReq.bufSize <= 0 || createReq.bufSize > TSDB_FUNC_BUF_SIZE) {
+  if (createReq.bufSize < 0 || createReq.bufSize > TSDB_FUNC_BUF_SIZE) {
     terrno = TSDB_CODE_MND_INVALID_FUNC_BUFSIZE;
     goto _OVER;
   }

source/dnode/mnode/impl/test/func/func.cpp

@@ -24,6 +24,7 @@ class MndTestFunc : public ::testing::Test {
 
   void SetCode(SCreateFuncReq* pReq, const char* pCode, int32_t size);
   void SetComment(SCreateFuncReq* pReq, const char* pComment);
+  void SetBufSize(SCreateFuncReq* pReq, int32_t size);
 };
 
 Testbase MndTestFunc::test;
@@ -40,6 +41,10 @@ void MndTestFunc::SetComment(SCreateFuncReq* pReq, const char* pComment) {
   strcpy(pReq->pComment, pComment);
 }
 
+void MndTestFunc::SetBufSize(SCreateFuncReq* pReq, int32_t size) {
+  pReq->bufSize = size;
+}
+
 TEST_F(MndTestFunc, 01_Show_Func) {
   test.SendShowReq(TSDB_MGMT_TABLE_FUNC, "user_functions", "");
   EXPECT_EQ(test.GetShowRows(), 0);
@@ -96,6 +101,7 @@ TEST_F(MndTestFunc, 02_Create_Func) {
     strcpy(createReq.name, "f1");
     SetCode(&createReq, "code1", 6);
     SetComment(&createReq, "comment1");
+    SetBufSize(&createReq, -1);
 
     int32_t contLen = tSerializeSCreateFuncReq(NULL, 0, &createReq);
     void*   pReq = rpcMallocCont(contLen);