highlight: do not reset existing highlights

* spot/twa/twa.hh (twa::get_or_set_named_prop): New method.
* spot/twaalgos/emptiness.cc, spot/twaalgos/isdet.cc: Use it to not
overwrite existing highlights.
* tests/core/det.test: Add test case.

spot/twa/twa.hh

@@ -957,8 +957,9 @@ namespace spot
     /// named properties.  They are used for instance to name all the
     /// state of an automaton.
     ///
-    /// This function attaches the object \a val to the current automaton,
-    /// under the name \a s.
+    /// This function attaches the object \a val to the current
+    /// automaton, under the name \a s and destroy any previous
+    /// property with the same name.
     ///
     /// When the automaton is destroyed, the \a destructor function will
     /// be called to destroy the attached object.
@@ -974,12 +975,12 @@ namespace spot
     /// named properties.  They are used for instance to name all the
     /// state of an automaton.
     ///
+    /// This function attaches the object \a val to the current
+    /// automaton, under the name \a s and destroy any previous
+    /// property with the same name.
     ///
-    /// This function attaches the object \a val to the current automaton,
-    /// under the name \a s.
-    ///
-    /// When the automaton is destroyed, the \a destructor function will
-    /// be called to destroy the attached object.
+    /// When the automaton is destroyed, the attached object will be
+    /// destroyed with \c delete.
     ///
     /// See https://spot.lrde.epita.fr/concepts.html#named-properties
     /// for a list of named properties used by Spot.
@@ -1019,11 +1020,35 @@ namespace spot
     template<typename T>
     T* get_named_prop(std::string s) const
     {
-      void* p = get_named_prop_(s);
-      if (!p)
+      if (void* p = get_named_prop_(s))
+        return static_cast<T*>(p);
+      else
         return nullptr;
-      return static_cast<T*>(p);
     }
+
+    /// \brief Create or retrieve a named property
+    ///
+    /// Arbitrary objects can be attached to automata.  Those are called
+    /// named properties.  They are used for instance to name all the
+    /// state of an automaton.
+    ///
+    /// This function create a property object of a given type, and
+    /// attached it to \a name if not such property exist, or it
+    /// returns
+    ///
+    /// See https://spot.lrde.epita.fr/concepts.html#named-properties
+    /// for a list of named properties used by Spot.
+    template<typename T>
+    T* get_or_set_named_prop(std::string s)
+    {
+      if (void* p = get_named_prop_(s))
+        return static_cast<T*>(p);
+
+      auto tmp = new T;
+      set_named_prop(s, tmp);
+      return tmp;
+    }
+
 #endif
 
     /// \brief Destroy all named properties.

spot/twaalgos/emptiness.cc

@@ -648,7 +648,8 @@ namespace spot
     if (!a)
       throw std::runtime_error("highlight() only work for twa_graph");
 
-    auto h = new std::map<unsigned, unsigned>; // highlighted edges
+    auto h = a->get_or_set_named_prop<std::map<unsigned, unsigned>>
+      ("highlight-edges");
 
     unsigned src = a->get_init_state_number();
     auto l = prefix.empty() ? &cycle : &prefix;
@@ -683,7 +684,6 @@ namespace spot
             }
         src = dst;
       }
-    a->set_named_prop("highlight-edges", h);
   }
 
   twa_graph_ptr

spot/twaalgos/isdet.cc

@@ -79,18 +79,24 @@ namespace spot
     if (aut->prop_deterministic())
       return;
     unsigned ns = aut->num_states();
-    auto* highlight = new std::map<unsigned, unsigned>;
+    auto* highlight = aut->get_or_set_named_prop<std::map<unsigned, unsigned>>
+      ("highlight-states");
+    bool deterministic = true;
     for (unsigned src = 0; src < ns; ++src)
       {
         bdd available = bddtrue;
         for (auto& t: aut->out(src))
           if (!bdd_implies(t.cond, available))
-            highlight->emplace(src, color);
+            {
+              (*highlight)[src] = color;
+              deterministic = false;
+            }
           else
-            available -= t.cond;
+            {
+              available -= t.cond;
+            }
       }
-    aut->prop_deterministic(highlight->empty());
-    aut->set_named_prop("highlight-states", highlight);
+    aut->prop_deterministic(deterministic);
   }
 
   void
@@ -99,7 +105,9 @@ namespace spot
     if (aut->prop_deterministic())
       return;
     unsigned ns = aut->num_states();
-    auto* highlight = new std::map<unsigned, unsigned>;
+    auto* highlight = aut->get_or_set_named_prop<std::map<unsigned, unsigned>>
+      ("highlight-edges");
+    bool deterministic = true;
     for (unsigned src = 0; src < ns; ++src)
       {
         // Make a first pass to gather non-deterministic labels
@@ -107,17 +115,21 @@ namespace spot
         bdd extra = bddfalse;
         for (auto& t: aut->out(src))
           if (!bdd_implies(t.cond, available))
-            extra |= (t.cond - available);
+            {
+              extra |= (t.cond - available);
+              deterministic = false;
+            }
           else
-            available -= t.cond;
+            {
+              available -= t.cond;
+            }
         // Second pass to gather the relevant edges.
-        if (extra != bddfalse)
+        if (!deterministic)
           for (auto& t: aut->out(src))
             if ((t.cond & extra) != bddfalse)
-              highlight->emplace(aut->get_graph().index_of_edge(t), color);
+              (*highlight)[aut->get_graph().index_of_edge(t)] = color;
       }
-    aut->prop_deterministic(highlight->empty());
-    aut->set_named_prop("highlight-edges", highlight);
+    aut->prop_deterministic(deterministic);
   }
 
   bool

tests/core/det.test

@@ -235,4 +235,43 @@ ltl2tgba -f 'Ga & FGb' -f 'Ga | FGb' > out.hoa
 test "`autfilt --nondet-states=1 --stats=%M out.hoa`" = "Ga & FGb"
 test "`autfilt --nondet-states=2 --stats=%M out.hoa`" = "Ga | FGb"
 
-true
+cat >input <<EOF
+HOA: v1.1
+name: "FGa"
+States: 2
+Start: 1
+AP: 1 "a"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+spot.highlight.edges: 1 3 2 3
+spot.highlight.states: 0 2
+--BODY--
+State: 0 {0}
+[0] 0
+State: 1
+[0] 0
+[t] 1
+--END--
+EOF
+autfilt -H1.1 --highlight-nondet=5 input > output
+cat >expected <<EOF
+HOA: v1.1
+name: "FGa"
+States: 2
+Start: 1
+AP: 1 "a"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+properties: trans-labels explicit-labels state-acc !complete
+properties: !deterministic
+spot.highlight.states: 0 2 1 5
+spot.highlight.edges: 1 3 2 5 3 5
+--BODY--
+State: 0 {0}
+[0] 0
+State: 1
+[0] 0
+[t] 1
+--END--
+EOF
+diff output expected