From f7c4d19df66c602d74795e98ce2ee4390d06fbb4 Mon Sep 17 00:00:00 2001
From: Yuqian Yang <crupest@crupest.life>
Date: Mon, 17 Nov 2025 13:52:52 +0800
Subject: Harden delete after free.

---
 src/ui/controls/Control.cpp | 17 +++++++++++++++--
 src/ui/controls/Window.cpp  | 33 +++++++++++++++++++++++----------
 2 files changed, 38 insertions(+), 12 deletions(-)

(limited to 'src/ui/controls')

diff --git a/src/ui/controls/Control.cpp b/src/ui/controls/Control.cpp
index e903b5b3..9c0fc537 100644
--- a/src/ui/controls/Control.cpp
+++ b/src/ui/controls/Control.cpp
@@ -1,4 +1,5 @@
 #include "cru/ui/controls/Control.h"
+#include "cru/base/log/Logger.h"
 #include "cru/ui/controls/Window.h"
 
 #include "cru/platform/gui/Cursor.h"
@@ -27,11 +28,14 @@ Control::Control() {
 Control::~Control() {
   if (auto window = GetWindow()) {
     if (window->IsInEventHandling()) {
-      // Don't delete control during event handling. Use DeleteLater.
-      std::terminate();
+      CRU_LOG_TAG_WARN(
+          "Better use delete later to delete control during event handling.");
     }
   }
 
+  if (auto window = GetWindow()) {
+    window->NotifyControlDestroyed(this);
+  }
   RemoveFromParent();
 }
 
@@ -58,6 +62,15 @@ void Control::SetParent(Control* parent) {
   OnParentChanged(old_parent, parent);
 }
 
+bool Control::HasAncestor(Control* control) {
+  auto parent = this;
+  while (parent) {
+    if (parent == control) return true;
+    parent = parent->GetParent();
+  }
+  return false;
+}
+
 void Control::RemoveFromParent() {
   if (parent_) {
     parent_->RemoveChild(this);
diff --git a/src/ui/controls/Window.cpp b/src/ui/controls/Window.cpp
index e6abc48d..c82b2485 100644
--- a/src/ui/controls/Window.cpp
+++ b/src/ui/controls/Window.cpp
@@ -265,16 +265,6 @@ void Window::SetOverrideCursor(std::shared_ptr<platform::gui::ICursor> cursor) {
 
 bool Window::IsInEventHandling() { return event_handling_count_; }
 
-void Window::UpdateCursor() {
-  if (override_cursor_) {
-    native_window_->SetCursor(override_cursor_);
-  } else {
-    const auto capture = GetMouseCaptureControl();
-    native_window_->SetCursor(
-        (capture ? capture : GetMouseHoverControl())->GetInheritedCursor());
-  }
-}
-
 void Window::OnNativeDestroy(platform::gui::INativeWindow* window,
                              std::nullptr_t) {
   CRU_UNUSED(window)
@@ -428,4 +418,27 @@ void Window::DispatchMouseHoverControlChangeEvent(Control* old_control,
   }
 }
 
+void Window::UpdateCursor() {
+  if (override_cursor_) {
+    native_window_->SetCursor(override_cursor_);
+  } else {
+    const auto capture = GetMouseCaptureControl();
+    native_window_->SetCursor(
+        (capture ? capture : GetMouseHoverControl())->GetInheritedCursor());
+  }
+}
+
+void Window::NotifyControlDestroyed(Control* control) {
+  if (focus_control_->HasAncestor(control)) {
+    focus_control_ = control->GetParent();
+  }
+
+  if (mouse_captured_control_->HasAncestor(control)) {
+    mouse_captured_control_ = control->GetParent();
+  }
+
+  if (mouse_hover_control_->HasAncestor(control)) {
+    mouse_hover_control_ = control->GetParent();
+  }
+}
 }  // namespace cru::ui::controls
-- 
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