refactor: disable 0 topics;

include/util/taoserror.h

@@ -558,6 +558,7 @@ int32_t* taosGetErrno();
 #define TSDB_CODE_TQ_GROUP_NOT_SET              TAOS_DEF_ERROR_CODE(0, 0x0A0B)
 #define TSDB_CODE_TQ_TABLE_SCHEMA_NOT_FOUND     TAOS_DEF_ERROR_CODE(0, 0x0A0C)
 #define TSDB_CODE_TQ_NO_COMMITTED_OFFSET        TAOS_DEF_ERROR_CODE(0, 0x0A0D)
+#define TSDB_CODE_TQ_NO_SUBSCRIBE_TOPICS        TAOS_DEF_ERROR_CODE(0, 0x0A0E)
 
 // wal
 // #define TSDB_CODE_WAL_APP_ERROR              TAOS_DEF_ERROR_CODE(0, 0x1000) // 2.x

source/client/src/clientTmq.c

@@ -1076,7 +1076,12 @@ int32_t tmq_subscribe(tmq_t* tmq, const tmq_list_t* topic_list) {
   SCMSubscribeReq req = {0};
   int32_t         code = 0;
 
-  tscDebug("consumer:0x%" PRIx64 " cgroup:%s, subscribe %d topics", tmq->consumerId, tmq->groupId, sz);
+  if (sz == 0) {
+    tscDebug("consumer:0x%" PRIx64 " cgroup:%s, subscribe %d topics, not allowed", tmq->consumerId, tmq->groupId, sz);
+    return TSDB_CODE_TQ_NO_SUBSCRIBE_TOPICS;
+  } else {
+    tscDebug("consumer:0x%" PRIx64 " cgroup:%s, subscribe %d topics", tmq->consumerId, tmq->groupId, sz);
+  }
 
   req.consumerId = tmq->consumerId;
   tstrncpy(req.clientId, tmq->clientId, 256);

source/util/src/terror.c

@@ -435,7 +435,8 @@ TAOS_DEFINE_ERROR(TSDB_CODE_TQ_META_KEY_NOT_IN_TXN,       "TQ meta key not in tx
 TAOS_DEFINE_ERROR(TSDB_CODE_TQ_META_KEY_DUP_IN_TXN,       "TQ met key dup in txn")
 TAOS_DEFINE_ERROR(TSDB_CODE_TQ_GROUP_NOT_SET,             "TQ group not exist")
 TAOS_DEFINE_ERROR(TSDB_CODE_TQ_TABLE_SCHEMA_NOT_FOUND,    "TQ table schema not found")
-TAOS_DEFINE_ERROR(TSDB_CODE_TQ_NO_COMMITTED_OFFSET,       "TQ no commited offset")
+TAOS_DEFINE_ERROR(TSDB_CODE_TQ_NO_COMMITTED_OFFSET,       "TQ no committed offset")
+TAOS_DEFINE_ERROR(TSDB_CODE_TQ_NO_SUBSCRIBE_TOPICS,       "TQ no topics")
 
 // wal
 TAOS_DEFINE_ERROR(TSDB_CODE_WAL_FILE_CORRUPTED,           "WAL file is corrupted")