fix:memset nullBitmap of SSDataBlock to 0 in udf

include/libs/function/taosudf.h

@@ -166,6 +166,8 @@ static FORCE_INLINE int32_t udfColEnsureCapacity(SUdfColumn *pColumn, int32_t ne
     if (tmp == NULL) {
       return TSDB_CODE_OUT_OF_MEMORY;
     }
+    uint32_t extend = BitmapLen(allocCapacity) - BitmapLen(data->rowsAlloc);
+    memset(tmp + BitmapLen(data->rowsAlloc), 0, extend);
     data->fixLenCol.nullBitmap = tmp;
     data->fixLenCol.nullBitmapLen = BitmapLen(allocCapacity);
     if (meta->type == TSDB_DATA_TYPE_NULL) {

source/common/src/tdatablock.c

@@ -314,7 +314,8 @@ int32_t colDataMergeCol(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, int
         if (btmp == NULL) {
           return TSDB_CODE_OUT_OF_MEMORY;
         }
-
+        uint32_t extend = BitmapLen(finalNumOfRows) - BitmapLen(numOfRow1);
+        memset(btmp + BitmapLen(numOfRow1), 0, extend);
         pColumnInfoData->nullbitmap = btmp;
       }