complement: reset the terminal property

Reported by Thomas Medioni.

* spot/twaalgos/complement.cc: Here.
* tests/core/complement.test: Add a test case.
* NEWS: Mention it.

NEWS

@@ -8,6 +8,10 @@ New in spot 2.3.2.dev (not yet released)
   - The output of 'genltl --r-left=1 --r-right=1 --format=%F'
     had typos.
 
+  - 'ltl2tgba Fa | autfilt --complement' would incorrectly claim that
+    the output is "terminal" because dtwa_complement() failed to reset
+    that property.
+
 New in spot 2.3.2 (2017-03-15)
 
   Tools:

spot/twaalgos/complement.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et
+// Copyright (C) 2013-2015, 2017 Laboratoire de Recherche et
 // Développement de l'Epita.
 //
 // This file is part of Spot, a model checking library.
@@ -18,7 +18,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <spot/twaalgos/complement.hh>
-#include <spot/twaalgos/sccinfo.hh>
+#include <spot/twaalgos/isdet.hh>
 #include <spot/twaalgos/complete.hh>
 #include <spot/twaalgos/cleanacc.hh>
 
@@ -27,9 +27,19 @@ namespace spot
   twa_graph_ptr
   dtwa_complement(const const_twa_graph_ptr& aut)
   {
+    if (!is_deterministic(aut))
+      throw
+        std::runtime_error("dtwa_complement() requires a deterministic input");
+
     // Simply complete the automaton, and complement its acceptance.
     auto res = cleanup_acceptance_here(complete(aut));
     res->set_acceptance(res->num_sets(), res->get_acceptance().complement());
+    // Complementing the acceptance is likely to break the terminal
+    // property, but not weakness.  We make a useless call to
+    // prop_keep() just so we remember to update it in the future if a
+    // new argument is added.
+    res->prop_keep({true, true, true, true, true});
+    res->prop_terminal(trival::maybe());
     return res;
   }
 }

tests/core/complement.test

@@ -1,6 +1,6 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2015, 2016 Laboratoire de Recherche et Développement de
+# Copyright (C) 2015-2017 Laboratoire de Recherche et Développement de
 # l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
@@ -22,12 +22,8 @@
 
 set -e
 
-autfilt=autfilt
-ltl2tgba=ltl2tgba
-randaut=randaut
-
-$randaut -H -A 'random 0..4' -Q1..10 -D -n 50 0..2 >aut
-run 0 $autfilt --complement -H aut >/dev/null
+randaut -H -A 'random 0..4' -Q1..10 -D -n 50 0..2 >aut
+run 0 autfilt --complement -H aut >/dev/null
 
 cat >in <<EOF
 HOA: v1
@@ -36,7 +32,7 @@ Acceptance: 0 t
 --BODY--
 --END--
 EOF
-$autfilt --complement -H in >out
+autfilt --complement -H in >out
 cat >expected <<EOF
 HOA: v1
 States: 1
@@ -54,7 +50,7 @@ EOF
 diff out expected
 
 
-$ltl2tgba -H 'GFa & GFb' Xa | $autfilt --complement -H >out
+ltl2tgba -H 'GFa & GFb' Xa Fa | autfilt --complement -H >out
 cat >expected <<EOF
 HOA: v1
 States: 1
@@ -78,7 +74,7 @@ AP: 1 "a"
 acc-name: co-Buchi
 Acceptance: 1 Fin(0)
 properties: trans-labels explicit-labels state-acc complete
-properties: deterministic terminal
+properties: deterministic weak
 --BODY--
 State: 0
 [0] 2
@@ -90,12 +86,27 @@ State: 2 {0}
 State: 3
 [t] 3
 --END--
+HOA: v1
+States: 2
+Start: 1
+AP: 1 "a"
+acc-name: co-Buchi
+Acceptance: 1 Fin(0)
+properties: trans-labels explicit-labels state-acc complete
+properties: deterministic stutter-invariant weak
+--BODY--
+State: 0 {0}
+[t] 0
+State: 1
+[0] 0
+[!0] 1
+--END--
 EOF
 diff out expected
 
 # The complement of a nondeterministic automaton is currently done via
 # a determinization.
-$ltl2tgba -H 'FGa' | $autfilt --complement >out
+ltl2tgba -H 'FGa' | autfilt --complement >out
 cat >expected <<EOF
 HOA: v1
 States: 2