[PATCH v2 3/3] user32: add hotpatchable wrapper for GetWindowLongA

[Yuxuan Shui]

From: Yuxuan Shui

ntlea for some reason expects GetWindowLongA to start with a "push $-2", and
will try to skip over this instruction. If we don't anticipate this, it will
ended up either skipping over critical instructions, or on a desync address.
Either way, it would be bad.
---
 dlls/user32/win.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/dlls/user32/win.c b/dlls/user32/win.c
index 28cf40441d9..bc5f55dbeb7 100644
--- a/dlls/user32/win.c
+++ b/dlls/user32/win.c
@@ -884,11 +884,23 @@ WORD WINAPI GetWindowWord( HWND hwnd, INT offset )
     return NtUserGetWindowWord( hwnd, offset );
 }

-
 /**********************************************************************
  *		GetWindowLongA (USER32.@)
  */
-LONG WINAPI GetWindowLongA( HWND hwnd, INT offset )
+
+#ifdef __i386__
+__ASM_STDCALL_FUNC(GetWindowLongA, 8,
+        "movl.s %edi, %edi\n"
+        "pushl %ebp\n"
+        "movl.s %esp, %ebp\n"
+        "pushl $-2\n"
+        "addl $4, %esp\n"
+        "popl %ebp\n"
+        "jmp " __ASM_STDCALL("RealGetWindowLongA", 8) "\n")
+LONG WINAPI RealGetWindowLongA( HWND hwnd, INT offset )
+#else
+LONG WINAPI DECLSPEC_HOTPATCH GetWindowLongA(HWND hwnd, INT offset)
+#endif
 {
     switch (offset)
     {
@@ -910,7 +922,6 @@ LONG WINAPI GetWindowLongA( HWND hwnd, INT offset )
     }
 }

-
 /**********************************************************************
  *		GetWindowLongW (USER32.@)
  */