Preserve the last error when restoring the error mode.

[Peter Rosin]

Hi!

As promised in the other thread, here's a patch (on top of the
thread-error-mode-2.patch) to ensure that the reported error is
the error from the LoadLibrary call.

Cheers,
Peter

2010-03-17  Peter Rosin  <p...@lysator.liu.se>

        Preserve the last error when restoring the error mode.
        * libltdl/loaders/loadlibrary.c (wm_open): Don't rely on
        SetThreadErrorMode (or SetErrorMode) to not clobber the last
        error.
        Report by Ralf Wildenhues.

--
They are in the crowd with the answer before the question.
> Why do you dislike Jeopardy?

diff --git a/libltdl/loaders/loadlibrary.c b/libltdl/loaders/loadlibrary.c
index 620e7cf..179c009 100644
--- a/libltdl/loaders/loadlibrary.c
+++ b/libltdl/loaders/loadlibrary.c
@@ -192,12 +192,16 @@ vm_open (lt_user_data LT__UNUSED loader_data, const char 
*filename,
   {
     /* Silence dialog from LoadLibrary on some failures. */
     DWORD errormode = getthreaderrormode ();
+    DWORD last_error;
+
     setthreaderrormode (errormode | SEM_FAILCRITICALERRORS, NULL);
 
     module = LoadLibrary (wpath);
 
     /* Restore the error mode. */
+    last_error = GetLastError ();
     setthreaderrormode (errormode, NULL);
+    SetLastError (last_error);
   }
 
   /* libltdl expects this function to fail if it is unable