SEGV with lalr1.cc

[Akim Demaille]

2003-01-13  Akim Demaille  <address@hidden>,
                Quoc Peyrot <address@hidden>,
                Robert Anisko <address@hidden>

        * 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.

Index: data/lalr1.cc
===================================================================
RCS file: /cvsroot/bison/bison/data/lalr1.cc,v
retrieving revision 1.18
diff -u -u -r1.18 lalr1.cc
--- data/lalr1.cc 26 Dec 2002 08:27:09 -0000 1.18
+++ data/lalr1.cc 13 Jan 2003 15:41:06 -0000
@@ -302,7 +302,10 @@
   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 @@
        }
 
       /* Pop the current state because it cannot handle the error token.  */
-      if (!state_stack_.height ())
+      if (state_stack_.height () == 1)
        goto yyabortlab;
 
 #if YYDEBUG