From 0e8aaebc00f18a642c9058c00f5ea6f52cd2b385 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Sat, 28 May 2022 20:18:41 +0200
Subject: [PATCH] xwayland: Make XSetIOErrorExitHandler() mandatory

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2718>
---
 config.h.meson              |  3 ---
 meson.build                 | 13 ++-----------
 src/wayland/meta-xwayland.c | 32 +++++++++++++-------------------
 3 files changed, 15 insertions(+), 33 deletions(-)

diff --git a/config.h.meson b/config.h.meson
index c7724b24f..d7fd48f9b 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -95,9 +95,6 @@
 /* Whether Xwayland has -listenfd option */
 #mesondefine HAVE_XWAYLAND_LISTENFD
 
-/* Whether libX11 has XSetIOErrorExitHandler */
-#mesondefine HAVE_XSETIOERROREXITHANDLER
-
 /* Whether the mkostemp function exists */
 #mesondefine HAVE_MKOSTEMP
 
diff --git a/meson.build b/meson.build
index 56ae4b807..43ea293dd 100644
--- a/meson.build
+++ b/meson.build
@@ -28,6 +28,7 @@ cairo_req = '>= 1.10.0'
 pangocairo_req = '>= 1.20'
 gsettings_desktop_schemas_req = '>= 40.alpha'
 json_glib_req = '>= 0.12.0'
+x11_req = '>= 1.7.0'
 xcomposite_req = '>= 0.4'
 xkbcommon_req = '>= 0.4.3'
 xfixes_req = '>= 6'
@@ -145,7 +146,7 @@ if not have_wayland and not have_x11
 endif
 
 if have_x11_client
-  x11_dep = dependency('x11')
+  x11_dep = dependency('x11', version: x11_req)
   xcomposite_dep = dependency('xcomposite', version: xcomposite_req)
   xcursor_dep = dependency('xcursor')
   xdamage_dep = dependency('xdamage')
@@ -591,15 +592,6 @@ if have_xwayland
   endif
 endif
 
-have_xsetioerrorexithandler = false
-if have_x11_client
-  if cc.has_function('XSetIOErrorExitHandler', dependencies: x11_dep,
-                    prefix: '''#include <X11/Xlib.h>''')
-    have_xsetioerrorexithandler = true
-    cdata.set('HAVE_XSETIOERROREXITHANDLER', 1)
-  endif
-endif
-
 optional_functions = [
   'mkostemp',
   'posix_fallocate',
@@ -678,7 +670,6 @@ summary('Documentation', have_documentation, section: 'Options')
 summary('Profiler', have_profiler, section: 'Options')
 summary('Xwayland initfd', have_xwayland_initfd, section: 'Options')
 summary('Xwayland listenfd', have_xwayland_listenfd, section: 'Options')
-summary('Safe X11 I/O errors', have_xsetioerrorexithandler, section: 'Options')
 summary('Xwayland terminate delay', have_xwayland_terminate_delay, section: 'Options')
 
 summary('Enabled', have_tests, section: 'Tests')
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index 44229eac0..a937f0ec8 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -455,16 +455,8 @@ meta_xwayland_terminate (MetaXWaylandManager *manager)
 static int
 x_io_error (Display *display)
 {
-  MetaWaylandCompositor *compositor = meta_wayland_compositor_get_default ();
-  MetaX11DisplayPolicy x11_display_policy;
-
   g_warning ("Connection to xwayland lost");
 
-  x11_display_policy =
-    meta_context_get_x11_display_policy (compositor->context);
-  if (x11_display_policy == META_X11_DISPLAY_POLICY_MANDATORY)
-    meta_exit (META_EXIT_ERROR);
-
   return 0;
 }
 
@@ -474,21 +466,30 @@ x_io_error_noop (Display *display)
   return 0;
 }
 
-#ifdef HAVE_XSETIOERROREXITHANDLER
 static void
 x_io_error_exit (Display *display,
                  void    *data)
 {
   MetaXWaylandManager *manager = data;
+  MetaContext *context = manager->compositor->context;
   MetaX11DisplayPolicy x11_display_policy;
 
   x11_display_policy =
-    meta_context_get_x11_display_policy (manager->compositor->context);
+    meta_context_get_x11_display_policy (context);
 
   if (x11_display_policy == META_X11_DISPLAY_POLICY_MANDATORY)
-    g_warning ("X Wayland crashed (X IO error)");
+    {
+      GError *error;
+
+      g_warning ("Xwayland terminated, exiting since it was mandatory");
+      error = g_error_new (G_IO_ERROR, G_IO_ERROR_FAILED,
+                           "Xwayland exited unexpectedly");
+      meta_context_terminate_with_error (context, error);
+    }
   else
-    meta_topic (META_DEBUG_WAYLAND, "Xwayland disappeared");
+    {
+      meta_topic (META_DEBUG_WAYLAND, "Xwayland disappeared");
+    }
 }
 
 static void
@@ -496,7 +497,6 @@ x_io_error_exit_noop (Display *display,
                       void    *data)
 {
 }
-#endif
 
 void
 meta_xwayland_override_display_number (int number)
@@ -1114,9 +1114,7 @@ meta_xwayland_setup_xdisplay (MetaXWaylandManager *manager,
      we won't reset the tty).
   */
   XSetIOErrorHandler (x_io_error);
-#ifdef HAVE_XSETIOERROREXITHANDLER
   XSetIOErrorExitHandler (xdisplay, x_io_error_exit, manager);
-#endif
 
   XFixesSetClientDisconnectMode (xdisplay, XFixesClientDisconnectFlagTerminate);
 }
@@ -1131,23 +1129,19 @@ meta_xwayland_connection_release (MetaXWaylandConnection *connection)
 void
 meta_xwayland_shutdown (MetaXWaylandManager *manager)
 {
-#ifdef HAVE_XSETIOERROREXITHANDLER
   MetaDisplay *display = meta_get_display ();
   MetaX11Display *x11_display;
-#endif
   char path[256];
 
   g_cancellable_cancel (manager->xserver_died_cancellable);
 
   XSetIOErrorHandler (x_io_error_noop);
-#ifdef HAVE_XSETIOERROREXITHANDLER
   x11_display = display->x11_display;
   if (x11_display)
     {
       XSetIOErrorExitHandler (meta_x11_display_get_xdisplay (x11_display),
                               x_io_error_exit_noop, NULL);
     }
-#endif
 
   meta_xwayland_terminate (manager);