to_parity: Improve to_parity and update tests

* spot/twaalgos/toparity.cc: Use a better search of the
transitions when we search compatible states.
* spot/twaalgos/toparity.hh: Use less that 80 columns.
* tests/python/merge.py, tests/python/toparity.py: Update tests.

spot/twaalgos/toparity.cc

@@ -833,13 +833,15 @@ const std::vector<unsigned>& states,
 std::map<unsigned, std::vector<unsigned>>& partial_history,
 state_2_car_scc& state_2_car)
 {
-    for (unsigned current_state : states)
+    for (auto& edge : aut->edges())
-        for (auto& edge : aut->out(current_state))
     {
         unsigned
             src = edge.src,
             dst = edge.dst;
-            if (src == dst)
+        // We don't change loops or transitions that were not created in
+        // the current SCC.
+        if (src == dst
+        || std::find(states.begin(), states.end(), src) == states.end())
             continue;
         unsigned dst_scc = num2car[dst].state_scc;
         auto cant_change = partial_history[aut->edge_number(edge)];

spot/twaalgos/toparity.hh

@@ -63,9 +63,9 @@ namespace spot
     /// Only allow degeneralization if it reduces the number of colors in the
     /// acceptance condition.
     bool reduce_col_deg = false;
-    /// Use propagate_marks_here to increase the number of marks on transition in
+    /// Use propagate_marks_here to increase the number of marks on transition
-    /// order to move more colors (and increase the number of compatible states)
+    /// in order to move more colors (and increase the number of
-    /// when we apply LAR.
+    /// compatible states) when we apply LAR.
     bool propagate_col  = true;
     /// If \a pretty_print is true, states of the output automaton are
     /// named to help debugging.

tests/python/merge.py

@@ -78,7 +78,8 @@ assert hoa == """HOA: v1
 States: 3
 Start: 0
 AP: 2 "a" "b"
-Acceptance: 2 Fin(1) | Inf(0)
+acc-name: parity min even 2
+Acceptance: 2 Inf(0) | Fin(1)
 properties: trans-labels explicit-labels trans-acc
 --BODY--
 State: 0

tests/python/toparity.py

@@ -288,7 +288,7 @@ State: 4
 [0&!1] 4
 [0&1] 4 {1 2 4}
 --END--
-"""), [9, 6, 6, 6, 7, 6, 6])
+"""), [9, 6, 7, 7, 6, 6, 6])
 
 test(spot.automaton("""
 HOA: v1