monitor: add a few tests

* src/tgbatest/monitor.test: New file.
* src/tgbatest/Makefile.am: Add it.
* src/tgbaalgos/minimize.cc (minimize_monitor): Mark
the output automaton as state-based.
* src/tgba/tgbagraph.hh: Assume automata with 0 acceptance sets are also
state-based.

src/tgba/tgbagraph.hh

@@ -322,6 +322,8 @@ namespace spot
 	}
       acc_.add_sets(num - acc_.num_sets());
       prop_single_acc_set(num == 1);
+      if (num == 0)
+	prop_state_based_acc();
     }
 
     acc_cond::mark_t set_single_acceptance_set()
@@ -430,7 +432,7 @@ namespace spot
 
     bool state_is_accepting(unsigned s) const
     {
-      assert(has_state_based_acc());
+      assert(has_state_based_acc() || acc_.num_sets() == 0);
       for (auto& t: g_.out(s))
 	// Stop at the first transition, since the remaining should be
 	// labeled identically.

src/tgbaalgos/minimize.cc

@@ -496,6 +496,7 @@ namespace spot
     auto res = minimize_dfa(det_a, final, non_final);
     res->prop_deterministic();
     res->prop_inherently_weak();
+    res->prop_state_based_acc();
     return res;
   }
 

src/tgbatest/Makefile.am

@@ -112,6 +112,7 @@ TESTS = \
   wdba.test \
   wdba2.test \
   babiak.test \
+  monitor.test \
   dra2dba.test \
   ltlcross4.test \
   ltl2dstar.test \

src/tgbatest/monitor.test

@@ -0,0 +1,75 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2014 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 3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+. ./defs
+
+set -e
+
+expect()
+{
+   cat >output.exp
+   run 0 "$@" > output.out
+   cat output.out
+   diff output.out output.exp
+}
+
+expect ../../bin/ltl2tgba --monitor a <<EOF
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="1", peripheries=2]
+  1 -> 2 [label="a"]
+  2 [label="0", peripheries=2]
+  2 -> 2 [label="1"]
+}
+EOF
+
+expect ../../bin/ltl2tgba --monitor a --hoa<<EOF
+HOA: v1
+name: "a"
+States: 2
+Start: 0
+AP: 1 "a"
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc deterministic
+--BODY--
+State: 0
+[0] 1
+State: 1
+[t] 1
+--END--
+EOF
+
+expect ../../bin/ltl2tgba --monitor GFa --hoa<<EOF
+HOA: v1
+name: "GFa"
+States: 1
+Start: 0
+AP: 0
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc complete deterministic
+--BODY--
+State: 0
+[t] 0
+--END--
+EOF