fix(query): check pointer before use it.

source/common/src/tdatablock.c

@@ -1880,9 +1880,6 @@ const char* blockCompressDecode(SSDataBlock* pBlock, int32_t numOfCols, int32_t
 
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
     if (IS_VAR_DATA_TYPE(pColInfoData->info.type)) {
-//      pColInfoData->varmeta.length = colLen[i];
-//      pColInfoData->varmeta.allocLen = colLen[i];
-
       memcpy(pColInfoData->varmeta.offset, pStart, sizeof(int32_t) * numOfRows);
       pStart += sizeof(int32_t) * numOfRows;
 

source/libs/function/src/builtinsimpl.c

@@ -1450,8 +1450,8 @@ void setSelectivityValue(SqlFunctionCtx* pCtx, SSDataBlock* pBlock, const STuple
   int32_t pageId = pTuplePos->pageId;
   int32_t offset = pTuplePos->offset;
 
-  int32_t numOfCols = taosArrayGetSize(pCtx->pSrcBlock->pDataBlock);
   if (pTuplePos->pageId != -1) {
+    int32_t numOfCols = taosArrayGetSize(pCtx->pSrcBlock->pDataBlock);
     SFilePage* pPage = getBufPage(pCtx->pBuf, pageId);
 
     bool* nullList = (bool*)((char*)pPage + offset);