Merge pull request #15715 from taosdata/fix/valgrindBug

fix; valgrind error

source/client/src/clientMain.c

@@ -809,6 +809,7 @@ void doAsyncQuery(SRequestObj *pRequest, bool updateMetaForce) {
 
   code = catalogAsyncGetAllMeta(pCxt->pCatalog, &conn, &catalogReq, retrieveMetaCallback, pWrapper,
                                 &pRequest->body.queryJob);
+  pCxt = NULL;
   if (code == TSDB_CODE_SUCCESS) {
     return;
   }
@@ -816,6 +817,8 @@ void doAsyncQuery(SRequestObj *pRequest, bool updateMetaForce) {
 _error:
   tscError("0x%" PRIx64 " error happens, code:%d - %s, reqId:0x%" PRIx64, pRequest->self, code, tstrerror(code),
            pRequest->requestId);
+  taosMemoryFree(pCxt);
+
   terrno = code;
   pRequest->code = code;
   pRequest->body.queryFp(pRequest->body.param, pRequest, code);