From 3a3ad6ad7ce779dd37cfe846e59f1890e050888a Mon Sep 17 00:00:00 2001
From: Yufeng He <40085740+he-yufeng@users.noreply.github.com>
Date: Sun, 21 Jun 2026 15:32:15 +0800
Subject: [PATCH] fix: skip empty tool entries in legacy dataset config
 extraction (#37669)

Signed-off-by: Yufeng He <40085740+he-yufeng@users.noreply.github.com>
---
 .../easy_ui_based_app/dataset/manager.py      |  5 ++++
 .../easy_ui_based_app/test_dataset_manager.py | 23 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/api/core/app/app_config/easy_ui_based_app/dataset/manager.py b/api/core/app/app_config/easy_ui_based_app/dataset/manager.py
index 3d857a4e9c0..be538455afb 100644
--- a/api/core/app/app_config/easy_ui_based_app/dataset/manager.py
+++ b/api/core/app/app_config/easy_ui_based_app/dataset/manager.py
@@ -213,6 +213,11 @@ class DatasetConfigManager:
             PlanningStrategy.REACT_ROUTER,
         }:
             for tool in config.get("agent_mode", {}).get("tools", []):
+                if not tool:
+                    # Skip malformed empty tool entries; list(tool.keys())[0]
+                    # would otherwise raise IndexError. The sibling convert()
+                    # already guards this with `if len(tool) == 1`.
+                    continue
                 key = list(tool.keys())[0]
                 if key == "dataset":
                     # old style, use tool name as key
diff --git a/api/tests/unit_tests/core/app/app_config/easy_ui_based_app/test_dataset_manager.py b/api/tests/unit_tests/core/app/app_config/easy_ui_based_app/test_dataset_manager.py
index d5305d2fc0b..e4e4f99c6d4 100644
--- a/api/tests/unit_tests/core/app/app_config/easy_ui_based_app/test_dataset_manager.py
+++ b/api/tests/unit_tests/core/app/app_config/easy_ui_based_app/test_dataset_manager.py
@@ -318,3 +318,26 @@ class TestIsDatasetExists:
             return_value=mock_dataset,
         )
         assert not DatasetConfigManager.is_dataset_exists("tenant1", valid_uuid)
+
+
+# ==============================
+# extract_dataset_config_for_legacy_compatibility tests
+# ==============================
+
+
+class TestExtractDatasetConfigForLegacyCompatibility:
+    def test_skips_empty_tool_entry(self):
+        # A malformed empty tool dict in agent_mode.tools must be skipped, not
+        # crash with `IndexError` on `list(tool.keys())[0]`. The sibling
+        # convert() already guards this with `if len(tool) == 1`.
+        config = {
+            "agent_mode": {
+                "enabled": True,
+                "strategy": PlanningStrategy.ROUTER,
+                "tools": [{}],
+            }
+        }
+
+        result = DatasetConfigManager.extract_dataset_config_for_legacy_compatibility("tenant1", AppMode.CHAT, config)
+
+        assert result["agent_mode"]["tools"] == [{}]