[reactos] 12/12: [WIN32K] Add some NULL checks for THREADINFO::rpdesk

[Timo Kreuzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=abb75b621472646b4bc06f...

commit abb75b621472646b4bc06f11e05c012358c85f35
Author:     Timo Kreuzer [e-mail]
AuthorDate: Mon Dec 26 16:11:14 2022 +0100
Commit:     Timo Kreuzer [e-mail]
CommitDate: Wed Jan 4 10:32:28 2023 +0100

[WIN32K] Add some NULL checks for THREADINFO::rpdesk

rpdesk should probably never be NULL, but it happens in rare circumstances, like csrss being terminated.
---
 win32ss/user/ntuser/desktop.c | 8 ++++++++
 win32ss/user/ntuser/window.c  | 2 +-
 win32ss/user/ntuser/winpos.c  | 4 ++--
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/win32ss/user/ntuser/desktop.c b/win32ss/user/ntuser/desktop.c
index 2344fea0c01..16b7aa0b8c2 100644
--- a/win32ss/user/ntuser/desktop.c
+++ b/win32ss/user/ntuser/desktop.c
@@ -1788,6 +1788,14 @@ BOOL IntDeRegisterShellHookWindow(HWND hWnd)
     PLIST_ENTRY ListEntry;
     PSHELL_HOOK_WINDOW Current;

+    // FIXME: This probably shouldn't happen, but it does
+    if (Desktop == NULL)
+    {
+        Desktop = IntGetActiveDesktop();
+        if (Desktop == NULL)
+            return FALSE;
+    }
+
     ListEntry = Desktop->ShellHookWindows.Flink;
     while (ListEntry != &Desktop->ShellHookWindows)
     {
diff --git a/win32ss/user/ntuser/window.c b/win32ss/user/ntuser/window.c
index 691b3f2996c..1c2b0474c08 100644
--- a/win32ss/user/ntuser/window.c
+++ b/win32ss/user/ntuser/window.c
@@ -493,7 +493,7 @@ static void IntSendDestroyMsg(HWND hWnd)
       }

/* If the window being destroyed is currently tracked... */
-      if (ti->rpdesk->spwndTrack == Window)
+      if (ti->rpdesk && ti->rpdesk->spwndTrack == Window)
       {
           IntRemoveTrackMouseEvent(ti->rpdesk);
       }
diff --git a/win32ss/user/ntuser/winpos.c b/win32ss/user/ntuser/winpos.c
index 79e29730f1e..f9ce2583b87 100644
--- a/win32ss/user/ntuser/winpos.c
+++ b/win32ss/user/ntuser/winpos.c
@@ -436,12 +436,12 @@ co_WinPosActivateOtherWindow(PWND Wnd)

// Find any window to bring to top. Works Okay for wine since it does not see X11 windows.
    WndTo = UserGetDesktopWindow();
-   WndTo = WndTo->spwndChild;
-   if ( WndTo == NULL )
+   if ((WndTo == NULL) || (WndTo->spwndChild == NULL))
    {
       //ERR("WinPosActivateOtherWindow No window!\n");
       return;
    }
+   WndTo = WndTo->spwndChild;
    for (;;)
    {
       if (WndTo == Wnd)