[pygobject] _pygi_marshal_from_py_uint64: Re-fix check of negative values

[Martin Pitt <martinpitt src gnome org>]

commit a2ab72aa39824579d1767d1fdba7e1031341f86c
Author: Martin Pitt <martinpitt gnome org>
Date:   Fri Oct 12 11:05:24 2012 +0200

    _pygi_marshal_from_py_uint64: Re-fix check of negative values
    
    Fix regression from commit 1bfcd5d94 (exposed by several test cases) when using
    Python 2.x.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=685000

 gi/pygi-marshal-from-py.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/gi/pygi-marshal-from-py.c b/gi/pygi-marshal-from-py.c
index 05a9b0c..b4c9fa0 100644
--- a/gi/pygi-marshal-from-py.c
+++ b/gi/pygi-marshal-from-py.c
@@ -565,13 +565,13 @@ _pygi_marshal_from_py_uint64 (PyGIInvokeState   *state,
 
 #if PY_VERSION_HEX < 0x03000000
     if (PyInt_Check (py_long)) {
-        guint64 long_ = (guint64) PyInt_AsLong (py_long);
-        if (long_ > G_MAXUINT64) {
+        long long_ =  PyInt_AsLong (py_long);
+        if (long_ < 0 || long_ > G_MAXUINT64) {
             PyErr_Format (PyExc_ValueError, "%" G_GUINT64_FORMAT " not in range %d to %" G_GUINT64_FORMAT,
                           (gint64) long_, 0, G_MAXUINT64);
             return FALSE;
         }
-        ulong_ = long_;
+        ulong_ = (guint64) long_;
     } else
 #endif
         ulong_ = PyLong_AsUnsignedLongLong (py_long);