From a1edbeb448d1104b8e9dd3181a04d45ff846a397 Mon Sep 17 00:00:00 2001
From: Tony <68118705+Legend-Master@users.noreply.github.com>
Date: Sat, 23 Aug 2025 14:21:55 +0800
Subject: [PATCH] fix(windows): emit LoopDestroyed on WM_ENDSESSION (#1126)

---
 .changes/wm-endsession.md               |  5 +++++
 src/platform_impl/windows/event_loop.rs | 20 +++++++++++++++++---
 src/platform_impl/windows/util.rs       |  1 +
 3 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 .changes/wm-endsession.md

diff --git a/.changes/wm-endsession.md b/.changes/wm-endsession.md
new file mode 100644
index 00000000..fc8a3966
--- /dev/null
+++ b/.changes/wm-endsession.md
@@ -0,0 +1,5 @@
+---
+tao: patch
+---
+
+Emit `Event::LoopDestroyed` on receiving `WM_ENDSESSION` message on Windows
diff --git a/src/platform_impl/windows/event_loop.rs b/src/platform_impl/windows/event_loop.rs
index d1a0a818..17fad672 100644
--- a/src/platform_impl/windows/event_loop.rs
+++ b/src/platform_impl/windows/event_loop.rs
@@ -22,7 +22,9 @@ use std::{
 use windows::{
   core::{s, BOOL, PCWSTR},
   Win32::{
-    Foundation::{HANDLE, HINSTANCE, HWND, LPARAM, LRESULT, POINT, RECT, WAIT_TIMEOUT, WPARAM},
+    Foundation::{
+      HANDLE, HINSTANCE, HWND, LPARAM, LRESULT, POINT, RECT, TRUE, WAIT_TIMEOUT, WPARAM,
+    },
     Graphics::Gdi::*,
     System::{
       LibraryLoader::GetModuleHandleW,
@@ -642,7 +644,7 @@ lazy_static! {
       RegisterWindowMessageA(s!("TaskbarCreated"))
     };
     static ref THREAD_EVENT_TARGET_WINDOW_CLASS: Vec<u16> = unsafe {
-        let class_name= util::encode_wide("Tao Thread Event Target");
+        let class_name = util::encode_wide("Tao Thread Event Target");
 
         let class = WNDCLASSEXW {
             cbSize: mem::size_of::<WNDCLASSEXW>() as u32,
@@ -650,7 +652,7 @@ lazy_static! {
             lpfnWndProc: Some(util::call_default_window_proc),
             cbClsExtra: 0,
             cbWndExtra: 0,
-            hInstance:HINSTANCE(GetModuleHandleW(PCWSTR::null()).unwrap_or_default().0),
+            hInstance: HINSTANCE(GetModuleHandleW(PCWSTR::null()).unwrap_or_default().0),
             hIcon: HICON::default(),
             hCursor: HCURSOR::default(), // must be null in order for cursor state to work properly
             hbrBackground: HBRUSH::default(),
@@ -2380,6 +2382,18 @@ unsafe extern "system" fn thread_event_target_callback<T: 'static>(
       DefSubclassProc(window, msg, wparam, lparam)
     }
 
+    // We don't process `WM_QUERYENDSESSION` yet until we introduce the same mechanism as Tauri's `ExitRequested` event
+    // win32wm::WM_QUERYENDSESSION => {}
+    win32wm::WM_ENDSESSION => {
+      // `wParam` is `FALSE` is for if the shutdown gets canceled,
+      // and we don't need to handle that case since we didn't do anything prior in response to `WM_QUERYENDSESSION`
+      if wparam.0 == TRUE.0 as usize {
+        subclass_input.event_loop_runner.loop_destroyed();
+      }
+      // Note: after we return 0 here, Windows will shut us down
+      LRESULT(0)
+    }
+
     _ if msg == *USER_EVENT_MSG_ID => {
       if let Ok(event) = subclass_input.user_event_receiver.recv() {
         subclass_input.send_event(Event::UserEvent(event));
diff --git a/src/platform_impl/windows/util.rs b/src/platform_impl/windows/util.rs
index b9d2f926..5605603d 100644
--- a/src/platform_impl/windows/util.rs
+++ b/src/platform_impl/windows/util.rs
@@ -291,6 +291,7 @@ pub type GetDpiForMonitor = unsafe extern "system" fn(
 type GetSystemMetricsForDpi =
   unsafe extern "system" fn(nindex: SYSTEM_METRICS_INDEX, dpi: u32) -> i32;
 pub type EnableNonClientDpiScaling = unsafe extern "system" fn(hwnd: HWND) -> BOOL;
+#[allow(non_snake_case)]
 pub type AdjustWindowRectExForDpi = unsafe extern "system" fn(
   rect: *mut RECT,
   dwStyle: WINDOW_STYLE,