fix some coverity issues

src/client/src/tscLocalMerge.c

@@ -315,7 +315,10 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
 
   pReducer->finalRowSize = tscGetResRowLength(pQueryInfo->exprList);
   pReducer->resColModel = finalmodel;
-  pReducer->resColModel->capacity = pReducer->nResultBufSize / pReducer->finalRowSize;
+  pReducer->resColModel->capacity = pReducer->nResultBufSize;
+  if (pReducer->finalRowSize > 0) {
+    pReducer->resColModel->capacity /= pReducer->finalRowSize;
+  }
   assert(pReducer->finalRowSize <= pReducer->rowSize);
 
   pReducer->pFinalRes = calloc(1, pReducer->rowSize * pReducer->resColModel->capacity);

src/client/src/tscParseInsert.c

@@ -802,7 +802,10 @@ static int32_t tscCheckIfCreateTable(char **sqlstr, SSqlObj *pSql) {
     }
 
     STableMetaInfo *pSTableMeterMetaInfo = tscGetMetaInfo(pQueryInfo, STABLE_INDEX);
-    tscSetTableFullName(pSTableMeterMetaInfo, &sToken, pSql);
+    code = tscSetTableFullName(pSTableMeterMetaInfo, &sToken, pSql);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
 
     tstrncpy(pTag->name, pSTableMeterMetaInfo->name, sizeof(pTag->name));
     code = tscGetTableMeta(pSql, pSTableMeterMetaInfo);

src/client/src/tscSubquery.c

@@ -936,8 +936,10 @@ static SJoinSupporter* tscUpdateSubqueryStatus(SSqlObj* pSql, int32_t numOfFetch
     }
   }
   
-  pState->numOfTotal = pSql->numOfSubs;
-  pState->numOfRemain = numOfFetch;
+  if (pState != NULL) {
+    pState->numOfTotal = pSql->numOfSubs;
+    pState->numOfRemain = numOfFetch;
+  }
   
   return pSupporter;
 }

src/cq/test/cqtest.c

@@ -76,7 +76,7 @@ int main(int argc, char *argv[]) {
   tdFreeSchema(pSchema);
 
   while (1) {
-    char c = getchar();
+    char c = (char)getchar();
     
     switch(c) {
       case 's':

src/query/src/qExecutor.c

@@ -5901,7 +5901,7 @@ int32_t qCreateQueryInfo(void *tsdb, int32_t vgId, SQueryTableMsg *pQueryMsg, qi
 
   if ((code = convertQueryMsg(pQueryMsg, &pTableIdList, &pExprMsg, &tagCond, &tbnameCond, &pGroupColIndex, &pTagColumnInfo)) !=
          TSDB_CODE_SUCCESS) {
-    return code;
+    goto _over;
   }
 
   if (pQueryMsg->numOfTables <= 0) {