check null ptr

source/dnode/vnode/src/tq/tqRead.c

@@ -695,13 +695,16 @@ int32_t tqRetrieveDataBlock2(SSDataBlock* pBlock, STqReader* pReader) {
             }
 #endif
             if (IS_STR_DATA_TYPE(colVal.type)) {
+              if (colVal.value.pData != NULL) {
                 char val[65535 + 2];
                 memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
                 varDataSetLen(val, colVal.value.nData);
                 if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                   goto FAIL;
                 }
-              /*val = colVal.value.pData;*/
+              } else {
+                colDataAppendNULL(pColData, i);
+              }
             } else {
               if (colDataAppend(pColData, i, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                 goto FAIL;
@@ -734,12 +737,16 @@ int32_t tqRetrieveDataBlock2(SSDataBlock* pBlock, STqReader* pReader) {
               continue;
             } else if (colVal.cid == pColData->info.colId) {
               if (IS_STR_DATA_TYPE(colVal.type)) {
+                if (colVal.value.pData != NULL) {
                   char val[65535 + 2];
                   memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
                   varDataSetLen(val, colVal.value.nData);
                   if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                     goto FAIL;
                   }
+                } else {
+                  colDataAppendNULL(pColData, i);
+                }
                 /*val = colVal.value.pData;*/
               } else {
                 if (colDataAppend(pColData, i, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {

source/dnode/vnode/src/tq/tqSink.c

@@ -762,7 +762,6 @@ void tqSinkToTablePipeline2(SStreamTask* pTask, void* vnode, int64_t ver, void*
   tqDebug("vgId:%d, task %d write into table, block num: %d", TD_VID(pVnode), pTask->taskId, blockSz);
 
   void*        pBuf = NULL;
-  int32_t      len = 0;
   SSubmitReq2* pReq = NULL;
   SArray*      tagArray = NULL;
   SArray*      pVals = NULL;
@@ -931,6 +930,7 @@ void tqSinkToTablePipeline2(SStreamTask* pTask, void* vnode, int64_t ver, void*
       taosMemoryFree(pTbData);
 
       // encode
+      int32_t len;
       int32_t code;
       tEncodeSize(tEncodeSSubmitReq2, pReq, len, code);
       SEncoder encoder;