Fix return of is_deterministic(), it was inverted.

Reported by Étienne Renault.

* src/tgbaalgos/isdet.cc (is_deterministic): Invert return code.
* src/tgbatest/nondet.test: New file.
* src/tgbatest/Makefile.am (TESTS): Add it.

src/tgbatest/nondet.test

@@ -0,0 +1,40 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2012 Laboratoire de Recherche et Développement
+# de l'Epita (LRDE).
+#
+# This file is part of Spot, a model checking library.
+#
+# Spot is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Spot is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Spot; see the file COPYING.  If not, write to the Free
+# Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+# 02111-1307, USA.
+
+. ./defs
+set -e
+
+../../bin/ltl2tgba FGa GFa --stats='%f %d' >out.1
+cat >expected.1<<EOF
+FGa 0
+GFa 1
+EOF
+
+cmp out.1 expected.1
+
+../../bin/ltl2tgba FGa GFa --stats='%f %d %n %s' >out.2
+cat >expected.2<<EOF
+FGa 0 1 2
+GFa 1 0 1
+EOF
+
+cmp out.2 expected.2