From 42bb82666356f04cdc3597f28131354dc1ceff53 Mon Sep 17 00:00:00 2001
From: cracyc <cracyc@users.noreply.github.com>
Date: Sat, 11 May 2024 15:45:53 -0500
Subject: [PATCH] make pointer in callproc32w16 null if invalid and special
 case nul in openfile16

---
 krnl386/file.c  | 15 ++++++++++-----
 krnl386/thunk.c |  5 ++++-
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/krnl386/file.c b/krnl386/file.c
index 2e330eee433..6b2935d1b63 100644
--- a/krnl386/file.c
+++ b/krnl386/file.c
@@ -804,11 +804,16 @@ HFILE16 WINAPI OpenFile16( LPCSTR name, OFSTRUCT *ofs, UINT16 mode )
                 }
                 goto error;
             }
-            pathw = strdupAtoW(path);
-            found = SearchPathW( pathw, filename, NULL, sizeof(ofs->szPathName),
-                                 pathname, NULL );
-            HeapFree( GetProcessHeap(), 0, path );
-            HeapFree( GetProcessHeap(), 0, pathw );
+            if (!wcsicmp(pathname, L"\\\\.\\nul"))
+                found = TRUE;
+            else
+            {
+                pathw = strdupAtoW(path);
+                found = SearchPathW( pathw, filename, NULL, sizeof(ofs->szPathName),
+                                     pathname, NULL );
+                HeapFree( GetProcessHeap(), 0, path );
+                HeapFree( GetProcessHeap(), 0, pathw );
+            }
             if (!found)
             {
                 RtlInitUnicodeString(&uni, pathname);
diff --git a/krnl386/thunk.c b/krnl386/thunk.c
index cf1e880661a..ce083fd0ae5 100644
--- a/krnl386/thunk.c
+++ b/krnl386/thunk.c
@@ -2531,7 +2531,10 @@ DWORD WINAPIV CallProc32W16( DWORD nrofargs, DWORD argconvmask, FARPROC proc32,
         {
             SEGPTR ptr = VA_ARG16( valist, SEGPTR );
             /* pascal convention, have to reverse the arguments order */
-            args[nrofargs - i - 1] = (DWORD)MapSL(ptr);
+            DWORD arg = (DWORD)MapSL(ptr);
+            if (!HIWORD(arg))
+                arg = 0;
+            args[nrofargs - i - 1] = arg;
             TRACE("%08x(%p),",ptr,MapSL(ptr));
         }
         else