wdba: adjust to work on any TωA

* src/twaalgos/minimize.cc, src/twaalgos/safety.cc,
src/twaalgos/safety.hh: Adjust.
* src/tests/wdba2.test: More tests.

src/tests/wdba2.test

@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2012, 2014 Laboratoire de Recherche et Développement
-# de l'Epita (LRDE).
+# Copyright (C) 2012, 2014, 2015 Laboratoire de Recherche et
+# Développement de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -37,3 +37,49 @@ run 0 ../ltl2tgba -Rm -kt 'Fa | XGd' > out2
 cmp out expected
 cmp out2 expected
 
+cat >input <<EOF
+HOA: v1
+name: "XXFp1"
+States: 5
+Start: 4
+AP: 1 "p1"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+properties: implicit-labels state-acc complete deterministic
+--BODY--
+State: 0 {0}
+0 0
+State: 1 {0}
+3 0
+State: 2
+1 1
+State: 3
+3 0
+State: 4
+2 2
+--END--
+EOF
+
+cat >expected <<EOF
+HOA: v1
+States: 4
+Start: 2
+AP: 1 "p1"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+properties: implicit-labels state-acc complete deterministic
+properties: inherently-weak
+--BODY--
+State: 0 {0}
+0 0
+State: 1
+3 3
+State: 2
+1 1
+State: 3
+3 0
+--END--
+EOF
+
+../../bin/autfilt --small --high -C -Hi input > output
+diff output expected