From 6ca5afd91dca3ad3626fbfd1b48c0737280ca5e5 Mon Sep 17 00:00:00 2001
From: zhaofangxun <zhaofangxun@uniontech.com>
Date: Thu, 8 Oct 2026 15:14:12 +0800
Subject: [PATCH] fix: prevent X11 IO error crash on mode switch
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1. Root cause: dde-shell does not install a custom X11 IO error
   handler, libX11 default _XDefaultIOError calls exit(1) on X
   connection death, triggering C++ static destructors that access
   the dead X11 connection, causing SIGSEGV
2. Fix: install custom x11IOErrorHandler calling _exit(0) to bypass
   C++ destructor chain, add X11 link dependency in CMakeLists.txt
3. Impact: only affects process exit path when X11 connection is
   lost, no behavior change for normal operation

Log: fix crash when switching from terminal mode to graphical mode

Influence:
1. Test switching from init 3 to init 5, verify no coredump
2. Verify normal desktop panel display and interaction
3. Verify no regression on existing dde-shell functionality

fix: 修复终端模式切换到图形化时的崩溃问题

1. 根因：dde-shell 未安装自定义 X11 IO 错误处理器，libX11 默认的
   _XDefaultIOError 在 X 连接断开时调用 exit(1)，触发 C++ 静态
   析构函数访问已断开的 X11 连接，导致 SIGSEGV
2. 方案：安装自定义 x11IOErrorHandler 调用 _exit(0) 绕过 C++ 析构
   链，并在 CMakeLists.txt 中添加 X11 链接依赖
3. 影响：仅影响 X11 连接断开时的进程退出路径，正常运行无行为变化

Log: 修复终端模式切换到图形化时的崩溃问题

Influence:
1. 测试 init 3 切换到 init 5 后 dde-shell 无 coredump
2. 验证桌面面板正常显示和交互
3. 验证现有 dde-shell 功能无回归

PMS: BUG-378799
---
 shell/CMakeLists.txt | 2 ++
 shell/main.cpp       | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/shell/CMakeLists.txt b/shell/CMakeLists.txt
index 8f6adb1c9..9770c64a9 100644
--- a/shell/CMakeLists.txt
+++ b/shell/CMakeLists.txt
@@ -6,6 +6,7 @@ find_package(Dtk${DTK_VERSION_MAJOR} COMPONENTS Widget REQUIRED)
 find_package(Qt${QT_VERSION_MAJOR} ${REQUIRED_QT_VERSION} REQUIRED COMPONENTS Widgets Gui WaylandClient)
 find_package(TreelandProtocols REQUIRED)
 pkg_check_modules(WaylandClient REQUIRED IMPORTED_TARGET wayland-client)
+pkg_check_modules(X11 REQUIRED IMPORTED_TARGET x11)
 
 if (NOT DEFINED SYSTEMD_USER_UNIT_DIR)
     find_package(PkgConfig REQUIRED)
@@ -48,6 +49,7 @@ target_link_libraries(dde-shell PRIVATE
     Dtk${DTK_VERSION_MAJOR}::Widget
     Qt${QT_VERSION_MAJOR}::DBus
     PkgConfig::WaylandClient
+    PkgConfig::X11
 )
 
 configure_file(${CMAKE_SOURCE_DIR}/misc/dde-shell-plugin@.service.in
diff --git a/shell/main.cpp b/shell/main.cpp
index aa7335652..77c13edf5 100644
--- a/shell/main.cpp
+++ b/shell/main.cpp
@@ -16,6 +16,8 @@
 
 #include <csignal>
 #include <iostream>
+#include <X11/Xlib.h>
+#include <unistd.h>
 
 #include "applet.h"
 #include "containment.h"
@@ -134,6 +136,11 @@ class AppletManager
     QList<DAppletLoader *> m_loaders;
 };
 
+static int x11IOErrorHandler(Display *)
+{
+    _exit(0);
+}
+
 int main(int argc, char *argv[])
 {
     setenv("DSG_APP_ID", "org.deepin.dde.shell", 0);
@@ -255,6 +262,8 @@ int main(int argc, char *argv[])
         manager.exec();
     }, Qt::QueuedConnection);
 
+    XSetIOErrorHandler(x11IOErrorHandler);
+
     QObject::connect(qApp, &QCoreApplication::aboutToQuit, qApp, [&manager]() {
         qCInfo(dsLog) << "Exit dde-shell.";
         DPluginLoader::instance()->destroy();