Paul Gofman : ntdll: Preserve untouched parts of xstate in set_thread_wow64_context().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 14a51fa4460d958efc22c2fe108d90c37b6465c1
URL:    https://gitlab.winehq.org/wine/wine/-/commit/14a51fa4460d958efc22c2fe108d90c...

Author: Paul Gofman <pgofman(a)codeweavers.com>
Date:   Mon Apr  8 17:37:00 2024 -0600

ntdll: Preserve untouched parts of xstate in set_thread_wow64_context().

---

 dlls/ntdll/unix/signal_x86_64.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index d8d16917942..4fc2727595d 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -1281,9 +1281,11 @@ NTSTATUS set_thread_wow64_context( HANDLE handle, const void *ctx, ULONG size )
     {
         CONTEXT_EX *context_ex = (CONTEXT_EX *)(context + 1);
         XSAVE_AREA_HEADER *xs = (XSAVE_AREA_HEADER *)((char *)context_ex + context_ex->XState.Offset);
+        UINT64 mask = frame->xstate.Mask;
 
         if (xstate_compaction_enabled) frame->xstate.CompactionMask |= xstate_extended_features();
         copy_xstate( &frame->xstate, xs, xs->Mask );
+        if (xs->CompactionMask) frame->xstate.Mask |= mask & ~xs->CompactionMask;
         frame->restore_flags |= CONTEXT_XSTATE;
     }
     return STATUS_SUCCESS;