diff --git a/reactos/include/reactos/wine/test.h b/reactos/include/reactos/wine/test.h
index af6480312d9..d0d8208926c 100644
--- a/reactos/include/reactos/wine/test.h
+++ b/reactos/include/reactos/wine/test.h
@@ -62,6 +62,9 @@ extern void winetest_end_todo( const char* platform );
 extern int winetest_get_mainargs( char*** pargv );
 extern void winetest_wait_child_process( HANDLE process );
 
+extern const char *wine_dbgstr_wn( const WCHAR *str, int n );
+static inline const char *wine_dbgstr_w( const WCHAR *s ) { return wine_dbgstr_wn( s, -1 ); }
+
 #ifdef STANDALONE
 #define START_TEST(name) \
   static void func_##name(void); \
@@ -196,6 +199,8 @@ typedef struct
     int current_line;                /* line of current check */
     int todo_level;                  /* current todo nesting level */
     int todo_do_loop;
+    char *str_pos;                   /* position in debug buffer */
+    char strings[2000];              /* buffer for debug strings */
 } tls_data;
 static DWORD tls_index;
 
@@ -208,13 +213,33 @@ static tls_data* get_tls_data(void)
     data=TlsGetValue(tls_index);
     if (!data)
     {
-        data=HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,sizeof(tls_data));
+        data=HeapAlloc(GetProcessHeap(), 0, sizeof(tls_data));
+        data->todo_level = 0;
+        data->str_pos = data->strings;
         TlsSetValue(tls_index,data);
     }
     SetLastError(last_error);
     return data;
 }
 
+/* allocate some tmp space for a string */
+static char *get_temp_buffer( size_t n )
+{
+    tls_data *data = get_tls_data();
+    char *res = data->str_pos;
+
+    if (res + n >= &data->strings[sizeof(data->strings)]) res = data->strings;
+    data->str_pos = res + n;
+    return res;
+}
+
+/* release extra space that we requested in gimme1() */
+static void release_temp_buffer( char *ptr, size_t size )
+{
+    tls_data *data = get_tls_data();
+    data->str_pos = ptr + size;
+}
+
 static void exit_process( int code )
 {
     fflush( stdout );
@@ -407,6 +432,62 @@ void winetest_wait_child_process( HANDLE process )
     }
 }
 
+const char *wine_dbgstr_wn( const WCHAR *str, int n )
+{
+    char *dst, *res;
+    size_t size;
+
+    if (!((ULONG_PTR)str >> 16))
+    {
+        if (!str) return "(null)";
+        res = get_temp_buffer( 6 );
+        sprintf( res, "#%04x", LOWORD(str) );
+        return res;
+    }
+    if (n == -1)
+    {
+        const WCHAR *end = str;
+        while (*end) end++;
+        n = end - str;
+    }
+    if (n < 0) n = 0;
+    size = 12 + min( 300, n * 5 );
+    dst = res = get_temp_buffer( size );
+    *dst++ = 'L';
+    *dst++ = '"';
+    while (n-- > 0 && dst <= res + size - 10)
+    {
+        WCHAR c = *str++;
+        switch (c)
+        {
+        case '\n': *dst++ = '\\'; *dst++ = 'n'; break;
+        case '\r': *dst++ = '\\'; *dst++ = 'r'; break;
+        case '\t': *dst++ = '\\'; *dst++ = 't'; break;
+        case '"':  *dst++ = '\\'; *dst++ = '"'; break;
+        case '\\': *dst++ = '\\'; *dst++ = '\\'; break;
+        default:
+            if (c >= ' ' && c <= 126)
+                *dst++ = c;
+            else
+            {
+                *dst++ = '\\';
+                sprintf(dst,"%04x",c);
+                dst+=4;
+            }
+        }
+    }
+    *dst++ = '"';
+    if (n > 0)
+    {
+        *dst++ = '.';
+        *dst++ = '.';
+        *dst++ = '.';
+    }
+    *dst++ = 0;
+    release_temp_buffer( res, dst - res );
+    return res;
+}
+
 /* Find a test by name */
 static const struct test *find_test( const char *name )
 {