diff --git a/ChangeLog b/ChangeLog
index ec2b2546d..09393903f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2003-06-30  Alexandre Duret-Lutz  <aduret@src.lip6.fr>
 
+	* src/tgbaparse/tgbaparse.yy (lines): Expect at last one line.
+
 	* doc/Doxyfile.in (HAVE_DOT): Set to YES to output
 	collaboration diagrams.
 	* doc/mainpage.dox: Typo.
@@ -10,14 +12,14 @@
 	(state_bdd_product::state_bdd_product): Adjust.
 	* src/tgba/tgbaproduct.cc (state_bdd_product::state_bdd_product):
 	Adjust.
-	
+
 	* src/tgba/succiter.hh (tgba_bdd_succ_iterator::done):
 	Mark as const.
-	* src/tgba/succiterconcrete.cc 
+	* src/tgba/succiterconcrete.cc
 	(tgba_succ_iterator_concrete::done): Likewise.
 	* src/tgba/succiterconcrete.hh
 	(tgba_succ_iterator_concrete::done): Likewise.
-	* src/tgba/tgbaexplicit.cc 
+	* src/tgba/tgbaexplicit.cc
 	(tgba_explicit_succ_iterator::done): Likewise.
 	* src/tgba/tgbaexplicit.hh
 	(tgba_explicit_succ_iterator::done): Likewise.
@@ -29,13 +31,13 @@
 	(tgba_translate_proxy_succ_iterator::done): Likewise.
 	* src/tgba/tgbatranslateproxy.cc
 	(tgba_translate_proxy_succ_iterator::done): Likewise.
-	
+
 	* src/tgba/succiterconcrete.cc
 	(tgba_succ_iterator_concrete::next): Call bdd_satoneset
 	on data_.varandnext_set.  The previous implementation
 	was wrong for GFa.
 	* src/tgba/tgbabddcoredata.hh: Declare varandnext_set.
-	* src/tgba/tgbabddcoredata.cc: Handle varandnext_set.	
+	* src/tgba/tgbabddcoredata.cc: Handle varandnext_set.
 
 	* doc/Doxygen.in: Enable LaTeX output.
 	* doc/Makefile.am (spotref.pdf): New rule.
diff --git a/src/ltlast/visitor.hh b/src/ltlast/visitor.hh
index 6535f2145..d39e32392 100644
--- a/src/ltlast/visitor.hh
+++ b/src/ltlast/visitor.hh
@@ -5,16 +5,16 @@
 
 namespace spot {
   namespace ltl {
-    
+
     /// \brief Formula visitor that can modify the formula.
     ///
-    /// Writing visitors is the prefered way 
+    /// Writing visitors is the prefered way
     /// to traverse a formula, since it doesn't
     /// involve any cast.
     ///
     /// If you do not need to modify the visited formula, inherit from
     /// spot::ltl:const_visitor instead.
-    struct visitor 
+    struct visitor
     {
       virtual void visit(atomic_prop* node) = 0;
       virtual void visit(constant* node) = 0;
@@ -25,13 +25,13 @@ namespace spot {
 
     /// \brief Formula visitor that cannot modify the formula.
     ///
-    /// Writing visitors is the prefered way 
+    /// Writing visitors is the prefered way
     /// to traverse a formula, since it doesn't
     /// involve any cast.
     ///
     /// If you want to modify the visited formula, inherit from
     /// spot::ltl:visitor instead.
-    struct const_visitor 
+    struct const_visitor
     {
       virtual void visit(const atomic_prop* node) = 0;
       virtual void visit(const constant* node) = 0;
diff --git a/src/tgbaparse/tgbaparse.yy b/src/tgbaparse/tgbaparse.yy
index 4ff53e2f2..50ab0568d 100644
--- a/src/tgbaparse/tgbaparse.yy
+++ b/src/tgbaparse/tgbaparse.yy
@@ -46,7 +46,8 @@ tgba: accepting_decl lines | lines;
 
 accepting_decl: ACC_DEF acc_decl ';'
 
-lines:
+/* At least one line.  */
+lines: line
        | lines line
        ;