From 4d91f5c8efa002d1c111e4db693298f4282feb62 Mon Sep 17 00:00:00 2001
From: Jacques Lucke <jacques@blender.org>
Date: Mon, 29 Sep 2025 13:54:08 +0200
Subject: [PATCH] Fix #146588: raise exception when attempting invalid
 idproperty renaming in Python

Each name has to be unique within a group, so when renaming an idproperty, one
has to make sure that the parent group does not contain duplicates afterwards.
This patch raises a `NameError` when setting the name to one that exists
already. Alternatively, one could delete the already-existing property, but that
seems unexpected and the user should rather do that explicitly.

This also adds a new unit test for this case.

Pull Request: https://projects.blender.org/blender/blender/pulls/146892
---
 source/blender/python/generic/idprop_py_api.cc | 9 +++++++++
 tests/python/bl_pyapi_idprop.py                | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/source/blender/python/generic/idprop_py_api.cc b/source/blender/python/generic/idprop_py_api.cc
index 52678016496..7913f36c8cd 100644
--- a/source/blender/python/generic/idprop_py_api.cc
+++ b/source/blender/python/generic/idprop_py_api.cc
@@ -272,6 +272,15 @@ static int BPy_IDGroup_SetName(BPy_IDProperty *self, PyObject *value, void * /*c
     PyErr_SetString(PyExc_TypeError, "string length cannot exceed 63 characters!");
     return -1;
   }
+  if (STREQ(name, self->prop->name)) {
+    return 0;
+  }
+  if (IDProperty *parent = self->parent) {
+    if (IDP_GetPropertyFromGroup(parent, name)) {
+      PyErr_SetString(PyExc_NameError, "property name already exists in parent group");
+      return -1;
+    }
+  }
 
   memcpy(self->prop->name, name, name_len + 1);
   return 0;
diff --git a/tests/python/bl_pyapi_idprop.py b/tests/python/bl_pyapi_idprop.py
index b6d876cc883..b281c733a5e 100644
--- a/tests/python/bl_pyapi_idprop.py
+++ b/tests/python/bl_pyapi_idprop.py
@@ -203,6 +203,14 @@ class TestIdPropertyCreation(TestHelper, unittest.TestCase):
         with self.assertRaises(TypeError):
             self.id[self.key_id] = self
 
+    def test_rename(self):
+        self.id["foo"] = {"a": 1}
+        self.id["bar"] = {"b": 2}
+        self.id["foo"].name = "foo"
+        self.id["bar"].name = "bar"
+        with self.assertRaises(NameError):
+            self.id["foo"].name = "bar"
+
 
 class TestIdPropertyUIData(TestHelper, unittest.TestCase):
     # Default testing idprop key identifier.