Address several issues reported by cppcheck all over the place.

* src/bin/common_finput.cc, src/tgbaalgos/lbtt.cc: Use !empty() instead
of size() > 0.
* src/bin/ltl2tgta.cc, src/kripke/kripkeexplicit.cc,
src/tgbatest/complementation.cc: Avoid useless assignments.
* src/bin/ltlcross.cc: Correct mistaken assignment inside assert().
* src/evtgba/symbol.hh, src/tgba/tgbabddcoredata.cc,
src/tgba/tgbabddcoredata.hh,
src/tgba/tgbasafracomplement.cc (operator=): Do not return a const
reference.
* src/evtgbatest/ltl2evtgba.cc, src/evtgbatest/product.cc,
src/evtgbatest/product.cc: Check indices before using them, not after.
* src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/tgbatest/randtgba.cc: Pass constant strings by reference.
* src/kripke/kripkeprint.cc, src/tgbaalgos/simulation.cc:
Remove a useless operation.
* src/ltlvisit/simplify.cc: Remove a duplicate condition.
* src/misc/formater.hh: Remove unused attribute.
* src/misc/modgray.cc: Initialize done_ in the constructor.
* src/saba/explicitstateconjunction.cc,
src/saba/explicitstateconjunction.hh (operator=): Fix prototype.
* src/saba/sabacomplementtgba.cc: Remove unused default constructor.
* src/ta/taexplicit.cc, src/ta/taproduct.cc, src/ta/tgtaproduct.cc,
src/ta/tgtaproduct.hh, src/taalgos/emptinessta.cc,
src/taalgos/minimize.cc, src/taalgos/reachiter.cc,
src/taalgos/tgba2ta.cc, src/tgbaalgos/cutscc.cc: Use C++ casts, and
++it instead of it++.
* src/taalgos/dotty.cc, src/tgbatest/ltl2tgba.cc: Refine the scope of
variables.
* src/tgba/tgbakvcomplement.hh (bdd_order): Always initialize bdd_.
* src/tgba/tgbasgba.cc, src/tgba/wdbacomp.cc: Use the initialization
line to initialize all members.

src/tgba/tgbabddcoredata.cc

@@ -90,7 +90,7 @@ namespace spot
     assert(dict == right.dict);
   }
 
-  const tgba_bdd_core_data&
+  tgba_bdd_core_data&
   tgba_bdd_core_data::operator=(const tgba_bdd_core_data& copy)
   {
     if (this != &copy)

src/tgba/tgbabddcoredata.hh

@@ -134,7 +134,7 @@ namespace spot
     tgba_bdd_core_data(const tgba_bdd_core_data& left,
 		       const tgba_bdd_core_data& right);
 
-    const tgba_bdd_core_data& operator=(const tgba_bdd_core_data& copy);
+    tgba_bdd_core_data& operator=(const tgba_bdd_core_data& copy);
 
     /// \brief Update the variable sets to take a new pair of variables into
     /// account.

src/tgba/tgbakvcomplement.hh

@@ -1,5 +1,6 @@
-// Copyright (C) 2009, 2010 Laboratoire de Recherche et Développement
-// de l'Epita (LRDE).
+// -*- coding: utf-8 -*-
+// Copyright (C) 2009, 2010, 2012 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -30,7 +31,7 @@ namespace spot
   {
   public:
     bdd_ordered()
-      : order_(0)
+      : bdd_(0), order_(0)
     {};
 
     bdd_ordered(int bdd_, unsigned order_)
@@ -77,7 +78,7 @@ namespace spot
   /// \endverbatim
   ///
   /// The original automaton is used as a States-based Generalized
-  /// Büchi Automaton.
+  /// Büchi Automaton.
   ///
   /// The construction is done on-the-fly, by the
   /// \c tgba_kv_complement_succ_iterator class.

src/tgba/tgbasafracomplement.cc

@@ -1,3 +1,4 @@
+// -*- coding: utf-8 -*-
 // Copyright (C) 2009, 2010, 2011, 2012 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 //
@@ -104,7 +105,7 @@ namespace spot
       safra_tree(const subset_t& nodes, safra_tree* p, int n);
       ~safra_tree();
 
-      const safra_tree& operator=(const safra_tree& other);
+      safra_tree& operator=(const safra_tree& other);
       int compare(const safra_tree* other) const;
       size_t hash() const;
 
@@ -177,7 +178,7 @@ namespace spot
         (*i)->destroy();
     }
 
-    const safra_tree&
+    safra_tree&
     safra_tree::operator=(const safra_tree& other)
     {
       if (this != &other)
@@ -816,7 +817,6 @@ namespace spot
 
       void print_safra_automaton(safra_tree_automaton* a)
       {
-        safra_tree_automaton::automaton_t node_list = a->automaton;
         typedef safra_tree_automaton::automaton_t::reverse_iterator
           automaton_cit;
         typedef safra_tree_automaton::transition_list::const_iterator

src/tgba/tgbasgba.cc

@@ -1,4 +1,4 @@
-// Copyright (C) 2009, 2011 Laboratoire de Recherche et Développement
+// Copyright (C) 2009, 2011, 2012 Laboratoire de Recherche et Développement
 // de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -101,9 +101,8 @@ namespace spot
       }
 
       tgba_sgba_proxy_succ_iterator(tgba_succ_iterator* it, bdd acc)
-	: it_(it), emulate_acc_cond_(true)
+	: it_(it), emulate_acc_cond_(true), acceptance_condition_(acc)
       {
-        acceptance_condition_ = acc;
       }
 
       virtual

src/tgba/wdbacomp.cc

@@ -166,9 +166,8 @@ namespace spot
     {
     public:
       tgba_wdba_comp_proxy(const tgba* a)
-	: a_(a)
+	: a_(a), the_acceptance_cond_(a->all_acceptance_conditions())
       {
-	the_acceptance_cond_ = a->all_acceptance_conditions();
 	if (the_acceptance_cond_ == bddfalse)
 	  {
 	    int v = get_dict()