feat: windows, custom client, update (#13687)

Signed-off-by: fufesou <linlong1266@gmail.com>

flutter/lib/common.dart

@@ -3938,7 +3938,9 @@ void earlyAssert() {
 
 void checkUpdate() {
   if (!isWeb) {
-    if (!bind.isCustomClient()) {
+    final isWindowsInstalled = isWindows && bind.mainIsInstalled();
+    final shouldCheckUpdate = isWindowsInstalled || !bind.isCustomClient();
+    if (shouldCheckUpdate) {
       platformFFI.registerEventHandler(
           kCheckSoftwareUpdateFinish, kCheckSoftwareUpdateFinish,
           (Map<String, dynamic> evt) async {

flutter/lib/desktop/pages/desktop_home_page.dart

@@ -430,10 +430,12 @@ class _DesktopHomePageState extends State<DesktopHomePage>
   }
 
   Widget buildHelpCards(String updateUrl) {
-    if (!bind.isCustomClient() &&
-        updateUrl.isNotEmpty &&
+    final isWindowsInstalled = isWindows && bind.mainIsInstalled();
+    if (updateUrl.isNotEmpty &&
         !isCardClosed &&
-        bind.mainUriPrefixSync().contains('rustdesk')) {
+        (isWindowsInstalled ||
+            (!bind.isCustomClient() &&
+                bind.mainUriPrefixSync().contains('rustdesk')))) {
       final isToUpdate = (isWindows || isMacOS) && bind.mainIsInstalled();
       String btnText = isToUpdate ? 'Update' : 'Download';
       GestureTapCallback onPressed = () async {

flutter/lib/desktop/pages/desktop_setting_page.dart

@@ -473,8 +473,7 @@ class _GeneralState extends State<_General> {
   }
 
   Widget other() {
-    final showAutoUpdate =
-        isWindows && bind.mainIsInstalled() && !bind.isCustomClient();
+    final showAutoUpdate = isWindows && bind.mainIsInstalled();
     final children = <Widget>[
       if (!isWeb && !bind.isIncomingOnly())
         _OptionCheckBox(context, 'Confirm before closing multiple tabs',

flutter/windows/runner/win32_window.cpp

@@ -7,6 +7,7 @@
 
 #include <cstdlib> // for getenv and _putenv
 #include <cstring> // for strcmp
+#include <string> // for std::wstring
 
 namespace {
 
@@ -15,6 +16,43 @@ constexpr const wchar_t kWindowClassName[] = L"FLUTTER_RUNNER_WIN32_WINDOW";
 // The number of Win32Window objects that currently exist.
 static int g_active_window_count = 0;
 
+// Static variable to hold the custom icon (needs cleanup on exit)
+static HICON g_custom_icon_ = nullptr;
+
+// Try to load icon from data\flutter_assets\assets\icon.ico if it exists.
+// Returns nullptr if the file doesn't exist or can't be loaded.
+HICON LoadCustomIcon() {
+  if (g_custom_icon_ != nullptr) {
+    return g_custom_icon_;
+  }
+  wchar_t exe_path[MAX_PATH];
+  if (!GetModuleFileNameW(nullptr, exe_path, MAX_PATH)) {
+    return nullptr;
+  }
+
+  std::wstring icon_path = exe_path;
+  size_t last_slash = icon_path.find_last_of(L"\\/");
+  if (last_slash == std::wstring::npos) {
+    return nullptr;
+  }
+
+  icon_path = icon_path.substr(0, last_slash + 1);
+  icon_path += L"data\\flutter_assets\\assets\\icon.ico";
+
+  // Check file attributes - reject if missing, directory, or reparse point (symlink/junction)
+  DWORD file_attr = GetFileAttributesW(icon_path.c_str());
+  if (file_attr == INVALID_FILE_ATTRIBUTES ||
+      (file_attr & FILE_ATTRIBUTE_DIRECTORY) ||
+      (file_attr & FILE_ATTRIBUTE_REPARSE_POINT)) {
+    return nullptr;
+  }
+
+  g_custom_icon_ = (HICON)LoadImageW(
+      nullptr, icon_path.c_str(), IMAGE_ICON, 0, 0,
+      LR_LOADFROMFILE | LR_DEFAULTSIZE);
+  return g_custom_icon_;
+}
+
 using EnableNonClientDpiScaling = BOOL __stdcall(HWND hwnd);
 
 // Scale helper to convert logical scaler values to physical using passed in
@@ -81,8 +119,16 @@ const wchar_t* WindowClassRegistrar::GetWindowClass() {
     window_class.cbClsExtra = 0;
     window_class.cbWndExtra = 0;
     window_class.hInstance = GetModuleHandle(nullptr);
-    window_class.hIcon =
-        LoadIcon(window_class.hInstance, MAKEINTRESOURCE(IDI_APP_ICON));
+    
+    // Try to load icon from data\flutter_assets\assets\icon.ico if it exists
+    HICON custom_icon = LoadCustomIcon();
+    if (custom_icon != nullptr) {
+      window_class.hIcon = custom_icon;
+    } else {
+      window_class.hIcon =
+          LoadIcon(window_class.hInstance, MAKEINTRESOURCE(IDI_APP_ICON));
+    }
+    
     window_class.hbrBackground = 0;
     window_class.lpszMenuName = nullptr;
     window_class.lpfnWndProc = Win32Window::WndProc;
@@ -95,6 +141,12 @@ const wchar_t* WindowClassRegistrar::GetWindowClass() {
 void WindowClassRegistrar::UnregisterWindowClass() {
   UnregisterClass(kWindowClassName, nullptr);
   class_registered_ = false;
+  
+  // Clean up the custom icon if it was loaded
+  if (g_custom_icon_ != nullptr) {
+    DestroyIcon(g_custom_icon_);
+    g_custom_icon_ = nullptr;
+  }
 }
 
 Win32Window::Win32Window() {