fix bug

src/client/src/tscSql.c

@@ -284,9 +284,10 @@ void taos_close(TAOS *taos) {
     return;
   }
 
+  if (RID_VALID(pObj->hbrid)) {
     SSqlObj* pHb = (SSqlObj*)taosAcquireRef(tscObjRef, pObj->hbrid);
     if (pHb != NULL) {
-    if (pHb->rpcRid > 0) {  // wait for rsp from dnode
+      if (RID_VALID(pHb->rpcRid)) {  // wait for rsp from dnode
         rpcCancelRequest(pHb->rpcRid);
         pHb->rpcRid = -1;
       }
@@ -295,6 +296,7 @@ void taos_close(TAOS *taos) {
       taosReleaseRef(tscObjRef, pHb->self);
       taos_free_result(pHb);
     }
+  }
 
   tscDebug("%p all sqlObj are freed, free tscObj and close dnodeConn:%p", pObj, pObj->pDnodeConn);
   taosRemoveRef(tscRefId, pObj->rid);

src/util/inc/tref.h

@@ -52,6 +52,8 @@ void *taosIterateRef(int rsetId, int64_t rid);
 // return the number of references in system
 int  taosListRef();  
 
+#define RID_VALID(x) ((x) > 0)
+
 /* sample code to iterate the refs 
 
 void demoIterateRefs(int rsetId) {