Fix assertion in scc.cc

ChangeLog

+2009-05-28  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	* src/tgbaalgos/scc.cc (scc_map::relabel_component): Make sure
+	that the old label of each state is strictly positive.  The
+	previous assertion (inherited from gtec) of "!= -1" is wrong,
+	because all negative values are now used to number SCCs.
+
 2009-05-26  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	* src/tgba/tgba.hh (format_state): s/automata who/automata that/.

src/tgbaalgos/scc.cc

-// Copyright (C) 2008  Laboratoire de Recherche et Developpement de
+// Copyright (C) 2008, 2009  Laboratoire de Recherche et Developpement de
 // l'Epita.
 //
 // This file is part of Spot, a model checking library.
@@ -87,7 +87,7 @@ namespace spot
 	hash_type::iterator spi = h_.find(*i);
 	assert(spi != h_.end());
 	assert(spi->first == *i);
-	assert(spi->second != -1);
+	assert(spi->second > 0);
 	spi->second = n;
       }
     scc_map_.insert(std::make_pair(n, root_.front()));