[TBASE-1112], and refactor some code.

src/client/src/tscServer.c

@@ -2460,10 +2460,10 @@ int tscBuildRetrieveFromMgmtMsg(SSqlObj *pSql) {
 
   pMsg += sizeof(SMgmtHead);
 
-  *((uint64_t *)pMsg) = pSql->res.qhandle;
+  *((uint64_t *) pMsg) = pSql->res.qhandle;
   pMsg += sizeof(pSql->res.qhandle);
 
-  *pMsg = htons(pCmd->type);
+  *((uint16_t*) pMsg) = htons(pCmd->type);
   pMsg += sizeof(pCmd->type);
 
   msgLen = pMsg - pStart;
@@ -3451,11 +3451,12 @@ int tscProcessRetrieveRspFromVnode(SSqlObj *pSql) {
   pRes->row = 0;
 
   /**
-   * If the query result is exhausted, the connection will be recycled.
-   * If current query is to free resource at server side, the connection will be recycle.
+   * If the query result is exhausted, or current query is to free resource at server side,
+   * the connection will be recycled.
    */
   if ((pRes->numOfRows == 0 && !(tscProjectionQueryOnMetric(pCmd) && pRes->offset > 0)) ||
       ((pCmd->type & TSDB_QUERY_TYPE_FREE_RESOURCE) == TSDB_QUERY_TYPE_FREE_RESOURCE)) {
+    tscTrace("%p no result or free resource, recycle connection", pSql);
     taosAddConnIntoCache(tscConnCache, pSql->thandle, pSql->ip, pSql->vnode, pObj->user);
     pSql->thandle = NULL;
   } else {

src/inc/taosmsg.h

@@ -673,7 +673,7 @@ typedef struct {
 
 typedef struct {
   uint64_t qhandle;
-  int16_t  free;
+  uint16_t free;
 } SRetrieveMeterMsg;
 
 typedef struct {

src/kit/shell/src/shellEngine.c

@@ -846,7 +846,7 @@ void shellGetGrantInfo(void *con) {
     TAOS_FIELD *fields = taos_fetch_fields(result);
     TAOS_ROW row = taos_fetch_row(result);
     if (row == NULL) {
-      fprintf(stderr, "\nGrant information is empty.\n");
+      fprintf(stderr, "\nFailed to grant information from server. Abort.\n");
       exit(0);
     }
 

src/system/detail/src/mgmtShell.c

@@ -873,7 +873,7 @@ int mgmtProcessRetrieveMsg(char *pMsg, int msgLen, SConnObj *pConn) {
     taosSendSimpleRsp(pConn->thandle, TSDB_MSG_TYPE_RETRIEVE_RSP, TSDB_CODE_MEMORY_CORRUPTED);
     return -1;
   } else {
-    if ((pRetrieve->free & TSDB_QUERY_TYPE_FREE_RESOURCE) == 0) {
+    if ((pRetrieve->free & TSDB_QUERY_TYPE_FREE_RESOURCE) != TSDB_QUERY_TYPE_FREE_RESOURCE) {
       rowsToRead = pShow->numOfRows - pShow->numOfReads;
     }
 
@@ -905,7 +905,7 @@ int mgmtProcessRetrieveMsg(char *pMsg, int msgLen, SConnObj *pConn) {
     pMsg = pRsp->data;
 
     // if free flag is set, client wants to clean the resources
-    if ((pRetrieve->free & TSDB_QUERY_TYPE_FREE_RESOURCE) == 0)
+    if ((pRetrieve->free & TSDB_QUERY_TYPE_FREE_RESOURCE) != TSDB_QUERY_TYPE_FREE_RESOURCE)
       rowsRead = (*mgmtRetrieveFp[pShow->type])(pShow, pRsp->data, rowsToRead, pConn);
 
     if (rowsRead < 0) {