python: fix return value of emptiness_check_instantiator

* wrap/python/spot.i: Fix typemap for
emptiness_check_instantiator::construct.  The previous code used
to turn (None, "error") into simply ("error").
* wrap/python/ajax/spot.in: Fix handling or errors when
instantiating emptiness checks.

ChangeLog

@@ -1,3 +1,13 @@
+2012-03-04  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	python: fix return value of emptiness_check_instantiator
+
+	* wrap/python/spot.i: Fix typemap for
+	emptiness_check_instantiator::construct.  The previous code used
+	to turn (None, "error") into simply ("error").
+	* wrap/python/ajax/spot.in: Fix handling or errors when
+	instantiating emptiness checks.
+
 2012-02-25  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	* NEWS: Summarize recent changes.

wrap/python/ajax/spot.in

@@ -489,6 +489,7 @@ if output_type == 'r':
     if not eci:
         unbufprint('<div class="parse-error">Cannot parse "' + opt
                          + '" near "' + err + '".</div>')
+        ec = 0
     else:
         ec_a = 0
         n_acc = degen.number_of_acceptance_conditions()

wrap/python/spot.i

@@ -110,8 +110,26 @@ using namespace spot;
 // function that return errors via a "char **err" argument.
 %typemap(in, numinputs=0) char** OUTPUT (char* temp)
   "$1 = &temp;";
-%typemap(argout, fragment="t_output_helper") char** OUTPUT
-  "$result = t_output_helper($result, SWIG_FromCharPtr(*$1));";
+%typemap(argout) char** OUTPUT {
+  PyObject *obj = SWIG_FromCharPtr(*$1);
+  if (!$result) {
+    $result = obj;
+  //# If the function returns null_ptr (i.e. Py_None), we
+  //# don't want to override it with OUTPUT as in the
+  //# default implementation of t_output_helper.
+  // } else if ($result == Py_None) {
+  //   Py_DECREF($result);
+  //   $result = obj;
+  } else {
+    if (!PyList_Check($result)) {
+      PyObject *o2 = $result;
+      $result = PyList_New(1);
+      PyList_SetItem($result, 0, o2);
+    }
+    PyList_Append($result,obj);
+    Py_DECREF(obj);
+  }
+ };
 %apply char** OUTPUT { char** err };
 
 // False and True cannot be redefined in Python3, even in a class.