From 5c8193bf1e8e3d00a97a23bf7c27007eaac5deca Mon Sep 17 00:00:00 2001
From: Campbell Barton <campbell@blender.org>
Date: Wed, 11 Jun 2025 15:22:43 +1000
Subject: [PATCH] Fix memory leak from builds without XR enabled

Even when built without XR, the window-manager properties
could be accessed & created but weren't freed.

Exposed by !140098.
---
 source/blender/windowmanager/intern/wm.cc       | 14 ++++++++++++++
 source/blender/windowmanager/xr/intern/wm_xr.cc |  7 +++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/source/blender/windowmanager/intern/wm.cc b/source/blender/windowmanager/intern/wm.cc
index 86ca0353496..7532f8fd4f4 100644
--- a/source/blender/windowmanager/intern/wm.cc
+++ b/source/blender/windowmanager/intern/wm.cc
@@ -554,6 +554,19 @@ void wm_add_default(Main *bmain, bContext *C)
   wm_window_make_drawable(wm, win);
 }
 
+static void wm_xr_data_free(wmWindowManager *wm)
+{
+  /* NOTE: this also runs when built without `WITH_XR_OPENXR`.
+   * It's necessary to prevent leaks when XR data is created or loaded into non XR builds.
+   * This can occur when Python reads all properties (see the `bl_rna_paths` test). */
+
+  /* Note that non-runtime data in `wm->xr` is freed as part of freeing the window manager.  */
+  if (wm->xr.session_settings.shading.prop) {
+    IDP_FreeProperty(wm->xr.session_settings.shading.prop);
+    wm->xr.session_settings.shading.prop = nullptr;
+  }
+}
+
 void wm_close_and_free(bContext *C, wmWindowManager *wm)
 {
   if (wm->autosavetimer) {
@@ -564,6 +577,7 @@ void wm_close_and_free(bContext *C, wmWindowManager *wm)
   /* May send notifier, so do before freeing notifier queue. */
   wm_xr_exit(wm);
 #endif
+  wm_xr_data_free(wm);
 
   while (wmWindow *win = static_cast<wmWindow *>(BLI_pophead(&wm->windows))) {
     /* Prevent draw clear to use screen. */
diff --git a/source/blender/windowmanager/xr/intern/wm_xr.cc b/source/blender/windowmanager/xr/intern/wm_xr.cc
index 72c77561481..c8936682af6 100644
--- a/source/blender/windowmanager/xr/intern/wm_xr.cc
+++ b/source/blender/windowmanager/xr/intern/wm_xr.cc
@@ -134,10 +134,9 @@ void wm_xr_exit(wmWindowManager *wm)
   if (wm->xr.runtime != nullptr) {
     wm_xr_runtime_data_free(&wm->xr.runtime);
   }
-  if (wm->xr.session_settings.shading.prop) {
-    IDP_FreeProperty(wm->xr.session_settings.shading.prop);
-    wm->xr.session_settings.shading.prop = nullptr;
-  }
+
+  /* See #wm_xr_data_free for logic that frees window-manager XR data
+   * that may exist even when built without XR. */
 }
 
 bool wm_xr_events_handle(wmWindowManager *wm)