fix: [ASAN] null pointer issue in builtinsimpl.c

source/libs/function/src/builtinsimpl.c

@@ -3376,7 +3376,8 @@ int32_t lastRowFunction(SqlFunctionCtx* pCtx) {
 
   int64_t* pts = (int64_t*)pInput->pPTS->pData;
   for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; ++i) {
-    char* data = colDataGetData(pInputCol, i);
+    bool  isNull = colDataIsNull(pInputCol, pInput->numOfRows, i, NULL);
+    char* data = isNull ? NULL : colDataGetData(pInputCol, i);
     TSKEY cts = pts[i];
 
     numOfElems++;