Autosave buffers on logout if HAVE_NTGUI

* src/w32fns.c (w32_wnd_proc): Pass a WM_ENDSESSION message on to
w32_read_socket.

* src/w32term.c (w32_read_socket): Create an event of type
END_SESSION_EVENT if a WM_ENDSESSION message is received.

* src/termhooks.h [HAVE_NTGUI]: New event kind END_SESSION_EVENT.

* src/keyboard.c [HAVE_NTGUI] (syms_of_keyboard): New symbol
`end-session'.
(kbd_buffer_get_event): Return an end-session event if an event of
type END_SESSION_EVENT is read.
(keys_of_keyboard): Bind the end-session event to kill-emacs in
special-event-map.  (Bug#23483)

4 files changed, 27 insertions, 0 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index 92d5c3053a7..fe04b3f2b5e 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -3893,6 +3893,16 @@ kbd_buffer_get_event (KBOARD **kbp,
           kbd_fetch_ptr = event + 1;
         }
 #endif
+
+#ifdef HAVE_NTGUI
+      else if (event->kind == END_SESSION_EVENT)
+        {
+          /* Make an event (end-session).  */
+          obj = list1 (Qend_session);
+          kbd_fetch_ptr = event + 1;
+        }
+#endif
+
 #if defined (HAVE_X11) || defined (HAVE_NTGUI) \
     || defined (HAVE_NS)
       else if (event->kind == ICONIFY_EVENT)
@@ -10984,6 +10994,7 @@ syms_of_keyboard (void)
 
 #ifdef HAVE_NTGUI
   DEFSYM (Qlanguage_change, "language-change");
+  DEFSYM (Qend_session, "end-session");
 #endif
 
 #ifdef HAVE_DBUS
@@ -11758,6 +11769,10 @@ keys_of_keyboard (void)
 
   initial_define_lispy_key (Vspecial_event_map, "delete-frame",
                             "handle-delete-frame");
+#ifdef HAVE_NTGUI
+  initial_define_lispy_key (Vspecial_event_map, "end-session",
+                            "kill-emacs");
+#endif
   initial_define_lispy_key (Vspecial_event_map, "ns-put-working-text",
                             "ns-put-working-text");
   initial_define_lispy_key (Vspecial_event_map, "ns-unput-working-text",
diff --git a/src/termhooks.h b/src/termhooks.h
index d21d6ce588a..ff74d99b7c1 100644
--- a/src/termhooks.h
+++ b/src/termhooks.h
@@ -158,6 +158,9 @@ enum event_kind
   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
   BUFFER_SWITCH_EVENT,          /* A process filter has switched buffers.  */
   DELETE_WINDOW_EVENT,          /* An X client said "delete this window".  */
+#ifdef HAVE_NTGUI
+  END_SESSION_EVENT,            /* The user is logging out or shutting down.  */
+#endif
   MENU_BAR_EVENT,               /* An event generated by the menu bar.
                                    The frame_or_window field's cdr holds the
                                    Lisp-level event value.
diff --git a/src/w32fns.c b/src/w32fns.c
index ede8f6be292..7a1f84a7bac 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -4795,6 +4795,11 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
       my_post_msg (&wmsg, hwnd, msg, wParam, lParam);
       return 0;
 
+    case WM_ENDSESSION:
+      my_post_msg (&wmsg, hwnd, msg, wParam, lParam);
+      /* If we return, the process will be terminated immediately.  */
+      sleep (1000);
+
     case WM_WINDOWPOSCHANGING:
       /* Don't restrict the sizing of any kind of frames.  If the window
          manager doesn't, there's no reason to do it ourselves.  */
diff --git a/src/w32term.c b/src/w32term.c
index 74ea6b543bd..72e1245ae59 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -5260,6 +5260,10 @@ w32_read_socket (struct terminal *terminal,
             }
           break;
 
+        case WM_ENDSESSION:
+          inev.kind = END_SESSION_EVENT;
+          break;
+
         case WM_INITMENU:
           f = x_window_to_frame (dpyinfo, msg.msg.hwnd);