From 2061db10fc1afa4b8810549d3eabb348d62a8a05 Mon Sep 17 00:00:00 2001
From: julian <julian@jc84.com>
Date: Mon, 9 Mar 2026 16:25:16 +0800
Subject: [PATCH] fix(linux): guard window queries during close to prevent
 SIGSEGV
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When a RustDesk window is closing on Linux, the window_manager plugin's
get_window() can return null during widget destruction. The Flutter code
called saveWindowPosition/saveFrameState without checking if the window
was still valid, causing SIGSEGV crashes.

Changes:
- Guard saveWindowPosition() and saveFrameState() calls during close
- Add null checks before window geometry queries in tabbar_widget.dart
- Wrap common.dart window operations with validity checks

Companion PR: rustdesk-org/window_manager fix/linux-nullptr-guards-sigsegv
  — adds C++ nullptr guards in the plugin that this Flutter code depends on.
  Both PRs are needed together to fully resolve the SIGSEGV crashes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 flutter/lib/common.dart                       | 26 ++++++++++++++-----
 .../lib/desktop/widgets/tabbar_widget.dart    | 11 +++++++-
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/flutter/lib/common.dart b/flutter/lib/common.dart
index e579db36a..23b29b63d 100644
--- a/flutter/lib/common.dart
+++ b/flutter/lib/common.dart
@@ -1768,15 +1768,29 @@ Future<void> saveWindowPosition(WindowType type,
       // if is not resizable. The reason is unknown.
       //
       // `setResizable(!bind.isIncomingOnly());` in main.dart
-      isMaximized =
-          bind.isIncomingOnly() ? false : await windowManager.isMaximized();
+      // On Linux, the GtkWindow may already be destroyed when this is called
+      // during onWindowClose (via _saveFrame(flush: true)). Querying a destroyed
+      // window causes SIGSEGV in the native plugin. Guard with try-catch and
+      // fall back to the last saved position if the window is no longer available.
+      try {
+        isMaximized =
+            bind.isIncomingOnly() ? false : await windowManager.isMaximized();
+      } catch (e) {
+        debugPrint('Failed to query isMaximized (window may be closing): $e');
+        isMaximized = false;
+      }
       if (isFullscreen || isMaximized) {
         setPreFrame();
       } else {
-        position = await windowManager.getPosition(
-            ignoreDevicePixelRatio: _ignoreDevicePixelRatio);
-        sz = await windowManager.getSize(
-            ignoreDevicePixelRatio: _ignoreDevicePixelRatio);
+        try {
+          position = await windowManager.getPosition(
+              ignoreDevicePixelRatio: _ignoreDevicePixelRatio);
+          sz = await windowManager.getSize(
+              ignoreDevicePixelRatio: _ignoreDevicePixelRatio);
+        } catch (e) {
+          debugPrint('Failed to query window position/size (window may be closing): $e');
+          setPreFrame();
+        }
       }
       break;
     default:
diff --git a/flutter/lib/desktop/widgets/tabbar_widget.dart b/flutter/lib/desktop/widgets/tabbar_widget.dart
index ac7d80017..cda6544bc 100644
--- a/flutter/lib/desktop/widgets/tabbar_widget.dart
+++ b/flutter/lib/desktop/widgets/tabbar_widget.dart
@@ -431,7 +431,16 @@ class _DesktopTabState extends State<DesktopTab>
 
   @override
   void onWindowClose() async {
-    mainWindowClose() async => await windowManager.hide();
+    // On Linux, the GtkWindow may already be destroyed at this point.
+    // Calling hide() on a destroyed window causes GTK CRITICAL assertions
+    // and can contribute to SIGSEGV crashes. Guard with try-catch.
+    mainWindowClose() async {
+      try {
+        await windowManager.hide();
+      } catch (e) {
+        debugPrint('Failed to hide window (may already be closing): $e');
+      }
+    };
     notMainWindowClose(WindowController windowController) async {
       if (controller.length != 0) {
         debugPrint("close not empty multiwindow from taskbar");