From af660af3390c166f640c71e46bb261c12e1d5e01 Mon Sep 17 00:00:00 2001
From: Zhaowenlong <zhaowenlong@gdngsk.com>
Date: Sat, 30 May 2026 17:11:24 +0800
Subject: [PATCH] =?UTF-8?q?fix:=20=E5=AE=8C=E5=96=84=E8=87=AA=E5=8A=A8?=
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---
 src/Mod/FreeCADExchange/AutoRouting.py        |  6 ++-
 .../freecad_exchange_auto_routing_test.py     | 43 +++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/Mod/FreeCADExchange/AutoRouting.py b/src/Mod/FreeCADExchange/AutoRouting.py
index fce56d0..9437829 100644
--- a/src/Mod/FreeCADExchange/AutoRouting.py
+++ b/src/Mod/FreeCADExchange/AutoRouting.py
@@ -1115,7 +1115,11 @@ def route_eplan_connection_between_terminals(
         raise
 
     if existing_replacements:
-        _remove_routing_connection_objects(doc, existing_replacements)
+        removed_existing = _remove_routing_connection_objects(doc, existing_replacements)
+        if removed_existing != len(existing_replacements):
+            if wire is not None:
+                _remove_routing_connection_objects(doc, [wire])
+            raise AutoRoutingError("Failed to replace existing routed connection.")
 
     try:
         doc.recompute()
diff --git a/tests/python/freecad_exchange_auto_routing_test.py b/tests/python/freecad_exchange_auto_routing_test.py
index f22aca8..bc77a15 100644
--- a/tests/python/freecad_exchange_auto_routing_test.py
+++ b/tests/python/freecad_exchange_auto_routing_test.py
@@ -504,6 +504,49 @@ class AutoRoutingTest(unittest.TestCase):
         self.assertEqual([first], routed_wires)
         self.assertEqual(0, len([obj for obj in doc.Objects if obj.Name == "Wire"]))
 
+    def test_eplan_connection_route_keeps_existing_wire_when_old_replacement_removal_fails(self):
+        _install_fake_freecad()
+        terminal_objects, wiring_objects, routing_network, auto_routing = _reload_modules()
+        app = sys.modules["FreeCAD"]
+        doc = FakeDocument()
+        terminal_objects.ensure_root_group(doc, "project-1")
+        start = _terminal(doc, terminal_objects, "TerminalStart", "terminal-start", app.Vector(0, 0, 0))
+        end = _terminal(doc, terminal_objects, "TerminalEnd", "terminal-end", app.Vector(100, 0, 0))
+        routing_network.create_route_carrier(
+            doc,
+            [app.Vector(0, 0, 20), app.Vector(100, 0, 20)],
+            project_uuid="project-1",
+            kind="WireDuct",
+        )
+        first = auto_routing.route_eplan_connection_between_terminals(
+            doc,
+            start,
+            end,
+            wire_uuid="wire-1",
+        )["wire"]
+        original_remove = auto_routing._remove_routing_connection_objects
+
+        def failing_remove(target_doc, objects):
+            if first in list(objects or []):
+                return 0
+            return original_remove(target_doc, objects)
+
+        auto_routing._remove_routing_connection_objects = failing_remove
+        try:
+            with self.assertRaises(auto_routing.AutoRoutingError):
+                auto_routing.route_eplan_connection_between_terminals(
+                    doc,
+                    start,
+                    end,
+                    wire_uuid="wire-1",
+                )
+        finally:
+            auto_routing._remove_routing_connection_objects = original_remove
+
+        routed_wires = list(wiring_objects.iter_routed_wire_objects(doc))
+
+        self.assertEqual([first], routed_wires)
+
     def test_route_carrier_styles_make_generated_objects_distinguishable(self):
         _install_fake_freecad()
         terminal_objects, _wiring_objects, routing_network, _auto_routing = _reload_modules()