diff --git a/ChangeLog b/ChangeLog
index 33b038c2..15d9871d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2003-01-13  Akim Demaille  <akim@epita.fr>,
+		Quoc Peyrot <chojin@lrde.epita.fr>,
+		Robert Anisko <anisko_r@lrde.epita.fr>
+
+	* data/lalr1.cc (parse::yyerrlab1): When popping the stack, stop
+	when the stacks contain one element, as the loop would otherwise
+	free the last state, and then use the top state (the one we just
+	popped).  This means that the initial elements will not be freed
+	explicitly, as is the case in yacc.c; it is not a problem, as
+	these elements have fake values.
+
 2003-01-11  Paul Eggert  <eggert@twinsun.com>
 
 	* NEWS: %expect-violations are now just warnings, reverting
diff --git a/data/lalr1.cc b/data/lalr1.cc
index bab5e5f6..a2329e3a 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -302,7 +302,10 @@ yy::]b4_parser_class_name[::parse ()
   int nerrs = 0;
   int errstatus = 0;
 
-  /* Initialize stack.  */
+  /* Initialize the stacks.  The initial state will be pushed in
+     yynewstate, since the latter expects the semantical and the
+     location values to have been already stored, initialize these
+     stacks with a primary value.  */
   state_stack_ = StateStack (0);
   semantic_stack_ = SemanticStack (1);
   location_stack_ = LocationStack (1);
@@ -545,7 +548,7 @@ b4_syncline([@oline@], [@ofile@])[
 	}
 
       /* Pop the current state because it cannot handle the error token.  */
-      if (!state_stack_.height ())
+      if (state_stack_.height () == 1)
 	goto yyabortlab;
 
 #if YYDEBUG