Merge pull request #10424 from taosdata/fix/TS-1215-D

[TS-1215]<fix>(query): memcpy with real length of data on DESC

src/query/src/qAggMain.c

@@ -3058,12 +3058,18 @@ static void col_project_function(SQLFunctionCtx *pCtx) {
 
   char *pData = GET_INPUT_DATA_LIST(pCtx);
   if (pCtx->order == TSDB_ORDER_ASC) {
+    // ASC
     int32_t numOfRows = (pCtx->param[0].i64 == 1)? 1:pCtx->size;
     memcpy(pCtx->pOutput, pData, (size_t) numOfRows * pCtx->inputBytes);
   } else {
+    // DESC
     for(int32_t i = 0; i < pCtx->size; ++i) {
-      memcpy(pCtx->pOutput + (pCtx->size - 1 - i) * pCtx->inputBytes, pData + i * pCtx->inputBytes,
-             pCtx->inputBytes);
+      char* dst = pCtx->pOutput + (pCtx->size - 1 - i) * pCtx->inputBytes;
+      char* src = pData + i * pCtx->inputBytes;
+      if (IS_VAR_DATA_TYPE(pCtx->inputType))
+        varDataCopy(dst, src);
+      else
+        memcpy(dst, src, pCtx->inputBytes);
     }
   }
 }