From 7f6a80c189adba4baf024bfdacf959ccbee9f364 Mon Sep 17 00:00:00 2001
From: wangt1xiuyi <13547954130@163.com>
Date: Mon, 11 Mar 2024 11:15:05 +0000
Subject: [PATCH] fix lead window function bug

---
 .../engine/window_function/ob_window_function_op.cpp   | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/sql/engine/window_function/ob_window_function_op.cpp b/src/sql/engine/window_function/ob_window_function_op.cpp
index 665a8b529..e8124ee35 100644
--- a/src/sql/engine/window_function/ob_window_function_op.cpp
+++ b/src/sql/engine/window_function/ob_window_function_op.cpp
@@ -702,6 +702,16 @@ int ObWindowFunctionOp::NonAggrCellLeadOrLag::eval(RowsReader &row_reader,
         LOG_WARN("invalid param", K(ret));
       } else if (OB_FAIL(params.at(j)->eval(op_.eval_ctx_, result))) {
         LOG_WARN("fail to calc result row", K(ret));
+      } else if (j == DEFAULT_VALUE && !result->is_null()) {
+        char *buf = NULL;
+        int64_t buf_size = result->get_deep_copy_size();
+        int64_t pos = 0;
+        if (OB_ISNULL(buf = wf_info_.expr_->get_str_res_mem(op_.eval_ctx_, buf_size))) {
+          ret = OB_ALLOCATE_MEMORY_FAILED;
+          LOG_WARN("failed to alloc", K(buf), K(ret));
+        } else if (OB_FAIL(lead_lag_params[j].deep_copy(*result, buf, buf_size, pos))) {
+          LOG_WARN("failed to deep copy datum", K(ret));
+        }
       } else {
         lead_lag_params[j] = *result;
         is_lead_lag_offset_used |= (j == OFFSET);