[PATCH v4 1/1] ntdll: Implement NtdllDefWindowProc_A().

[Aida Jonikienė]

From: Aida Jonikienė

The Crinkler linker redirects the DefWindowProcA calls to the
NtdllDefWindowProc_A function (which doesn't exist on Wine)
and so it picks the first export in ntdll (which is A_SHAFinal right now)
which obviously causes a segfault (this is problematic for the application
listed in the bug report).

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53321
---
 dlls/ntdll/misc.c     | 26 ++++++++++++++++++++++++++
 dlls/ntdll/ntdll.spec |  1 +
 2 files changed, 27 insertions(+)

diff --git a/dlls/ntdll/misc.c b/dlls/ntdll/misc.c
index ab01c77531c..a2037ebd4de 100644
--- a/dlls/ntdll/misc.c
+++ b/dlls/ntdll/misc.c
@@ -501,3 +501,29 @@ ULONG WINAPIV EtwTraceMessage( TRACEHANDLE handle, ULONG flags, LPGUID guid, /*U
     va_end( valist );
     return ret;
 }
+
+/******************************************************************************
+ *                  NtdllDefWindowProc_A (NTDLL.@)
+ */
+LRESULT WINAPI NtdllDefWindowProc_A( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam )
+{
+    LPARAM (WINAPI *pDefWindowProcA)(HWND,UINT,WPARAM,LPARAM); /* DefWindowProcA */
+    const UNICODE_STRING name = RTL_CONSTANT_STRING( L"user32.dll" );
+    NTSTATUS status;
+    HMODULE module;
+
+    if ((status = LdrGetDllHandle( NULL, 0, &name, &module )))
+    {
+        ERR("Failed to get user32.dll handle, status %08lx\n", status);
+        return 0; /* FIXME: Is this a good way to indicate failure? */
+    }
+
+    pDefWindowProcA = RtlFindExportedRoutineByName( module, "DefWindowProcA" );
+    if (!pDefWindowProcA)
+    {
+        ERR("Cannot find the function\n");
+        return 0; /* FIXME: Is this a good way to indicate failure? */
+    }
+
+    return pDefWindowProcA( hwnd, msg, wParam, lParam );
+}
diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index 014c221e59f..79bcfbe2e74 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -455,6 +455,7 @@
 # @ stub NtWriteRequestData
 @ stdcall -syscall NtWriteVirtualMemory(long ptr ptr long ptr)
 @ stdcall -syscall NtYieldExecution()
+@ stdcall NtdllDefWindowProc_A(long long long long)
 @ stub PfxFindPrefix
 @ stub PfxInitialize
 @ stub PfxInsertPrefix