[reactos] 01/01: [NTUSER] Check class name existence on IntGetAtomFromStringOrAtom (#6184)

[Katayama Hirofumi MZ]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=9a9b22aac1279c69b2d1c…

commit 9a9b22aac1279c69b2d1c373093ca64251d71077
Author:     Katayama Hirofumi MZ <katayama.hirofumi.mz(a)gmail.com>
AuthorDate: Wed Jan 10 08:01:37 2024 +0900
Commit:     GitHub <noreply(a)github.com>
CommitDate: Wed Jan 10 08:01:37 2024 +0900

    [NTUSER] Check class name existence on IntGetAtomFromStringOrAtom (#6184)
    
    Based on I_Kill_Bugs' class_error.patch.
    JIRA issue: CORE-13422, CORE-7531, CORE-18639
---
 win32ss/user/ntuser/class.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/win32ss/user/ntuser/class.c b/win32ss/user/ntuser/class.c
index 548bef255e6..1ad90351265 100644
--- a/win32ss/user/ntuser/class.c
+++ b/win32ss/user/ntuser/class.c
@@ -1355,9 +1355,17 @@ IntGetAtomFromStringOrAtom(
     }
     else
     {
-        ASSERT(IS_ATOM(ClassName->Buffer));
-        *Atom = (RTL_ATOM)((ULONG_PTR)ClassName->Buffer);
-        Ret = TRUE;
+        if (ClassName->Buffer)
+        {
+            *Atom = (RTL_ATOM)((ULONG_PTR)ClassName->Buffer);
+            Ret = TRUE;
+        }
+        else
+        {
+            *Atom = 0;
+            EngSetLastError(ERROR_CLASS_DOES_NOT_EXIST);
+            Ret = FALSE;
+        }
     }
 
     return Ret;