--- a/Python/ast.c	Sun Jun 28 17:32:20 2009 +0000
+++ b/Python/ast.c	Sun Jun 28 19:19:51 2009 +0000
@@ -362,12 +362,12 @@
 };
 
 static int
-forbidden_name(expr_ty e, const node *n)
+forbidden_name(identifier name, const node *n)
 {
     const char **p;
-    assert(PyUnicode_Check(e->v.Name.id));
+    assert(PyUnicode_Check(name));
     for (p = FORBIDDEN; *p; p++) {
-        if (PyUnicode_CompareWithASCIIString(e->v.Name.id, *p) == 0) {
+        if (PyUnicode_CompareWithASCIIString(name, *p) == 0) {
             ast_error(n, "assignment to keyword");
             return 1;
         }
@@ -414,7 +414,7 @@
             break;
         case Name_kind:
             if (ctx == Store) {
-                if (forbidden_name(e, n))
+                if (forbidden_name(e->v.Name.id, n))
                     return 0; /* forbidden_name() calls ast_error() */
             }
             e->v.Name.ctx = ctx;
@@ -424,10 +424,13 @@
             s = e->v.List.elts;
             break;
         case Tuple_kind:
-            if (asdl_seq_LEN(e->v.Tuple.elts) == 0) 
-                return ast_error(n, "can't assign to ()");
-            e->v.Tuple.ctx = ctx;
-            s = e->v.Tuple.elts;
+            if (asdl_seq_LEN(e->v.Tuple.elts))  {
+                e->v.Tuple.ctx = ctx;
+                s = e->v.Tuple.elts;
+            }
+            else {
+                expr_name = "()";
+            }
             break;
         case Lambda_kind:
             expr_name = "lambda";
@@ -1378,7 +1381,7 @@
         /* testlist_comp: test ( comp_for | (',' test)* [','] ) */ 
         if ((NCH(ch) > 1) && (TYPE(CHILD(ch, 1)) == comp_for))
             return ast_for_genexp(c, ch);
-        
+
         return ast_for_testlist(c, ch);
     case LSQB: /* list (or list comprehension) */
         ch = CHILD(n, 1);
@@ -1513,14 +1516,7 @@
 
     ch = CHILD(n, NCH(n) - 1);
     if (TYPE(ch) == sliceop) {
-        if (NCH(ch) == 1) {
-            /* No expression, so step is None */
-            ch = CHILD(ch, 0);
-            step = Name(new_identifier("None", c->c_arena), Load,
-                        LINENO(ch), ch->n_col_offset, c->c_arena);
-            if (!step)
-                return NULL;
-        } else {
+        if (NCH(ch) != 1) {
             ch = CHILD(ch, 1);
             if (TYPE(ch) == test) {
                 step = ast_for_expr(c, ch);
@@ -2014,7 +2010,7 @@
                 } else if (e->kind != Name_kind) {
                   ast_error(CHILD(ch, 0), "keyword can't be an expression");
                   return NULL;
-                } else if (forbidden_name(e, ch)) {
+                } else if (forbidden_name(e->v.Name.id, ch)) {
 		  return NULL;
 		}
                 key = e->v.Name.id;
@@ -2160,6 +2156,7 @@
     }
 }
 
+
 static asdl_seq *
 ast_for_exprlist(struct compiling *c, const node *n, expr_context_ty context)
 {
@@ -2260,49 +2257,64 @@
 }
 
 static alias_ty
-alias_for_import_name(struct compiling *c, const node *n)
+alias_for_import_name(struct compiling *c, const node *n, int store)
 {
     /*
       import_as_name: NAME ['as' NAME]
       dotted_as_name: dotted_name ['as' NAME]
       dotted_name: NAME ('.' NAME)*
     */
-    PyObject *str, *name;
+    identifier str, name;
 
  loop:
     switch (TYPE(n)) {
-        case import_as_name:
+         case import_as_name: {
+            node *name_node = CHILD(n, 0);
             str = NULL;
+            name = NEW_IDENTIFIER(name_node);
+            if (!name)
+                return NULL;
             if (NCH(n) == 3) {
-                str = NEW_IDENTIFIER(CHILD(n, 2));
+                node *str_node = CHILD(n, 2);
+                str = NEW_IDENTIFIER(str_node);
                 if (!str)
                     return NULL;
+                if (store && forbidden_name(str, str_node))
+                    return NULL;
             }
-            name = NEW_IDENTIFIER(CHILD(n, 0));
-            if (!name)
-                return NULL;
+            else {
+                if (forbidden_name(name, name_node))
+                    return NULL;
+            }
             return alias(name, str, c->c_arena);
+        }
         case dotted_as_name:
             if (NCH(n) == 1) {
                 n = CHILD(n, 0);
                 goto loop;
             }
             else {
-                alias_ty a = alias_for_import_name(c, CHILD(n, 0));
+                node *asname_node = CHILD(n, 2);
+                alias_ty a = alias_for_import_name(c, CHILD(n, 0), 0);
                 if (!a)
                     return NULL;
                 assert(!a->asname);
-                a->asname = NEW_IDENTIFIER(CHILD(n, 2));
+                a->asname = NEW_IDENTIFIER(asname_node);
                 if (!a->asname)
                     return NULL;
+                if (forbidden_name(a->asname, asname_node))
+                    return NULL;
                 return a;
             }
             break;
         case dotted_name:
             if (NCH(n) == 1) {
-                name = NEW_IDENTIFIER(CHILD(n, 0));
+                node *name_node = CHILD(n, 0);
+                name = NEW_IDENTIFIER(name_node);
                 if (!name)
                     return NULL;
+                if (store && forbidden_name(name, name_node))
+                    return NULL;
                 return alias(name, NULL, c->c_arena);
             }
             else {
@@ -2382,7 +2394,7 @@
         if (!aliases)
                 return NULL;
         for (i = 0; i < NCH(n); i += 2) {
-            alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
+            alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
             if (!import_alias)
                 return NULL;
             asdl_seq_SET(aliases, i / 2, import_alias);
@@ -2393,13 +2405,15 @@
         int n_children;
         int idx, ndots = 0;
         alias_ty mod = NULL;
-        identifier modname;
+        identifier modname = NULL;
         
        /* Count the number of dots (for relative imports) and check for the
           optional module name */
         for (idx = 1; idx < NCH(n); idx++) {
             if (TYPE(CHILD(n, idx)) == dotted_name) {
-                mod = alias_for_import_name(c, CHILD(n, idx));
+                mod = alias_for_import_name(c, CHILD(n, idx), 0);
+                if (!mod)
+                    return NULL;
                 idx++;
                 break;
             } else if (TYPE(CHILD(n, idx)) == ELLIPSIS) {
@@ -2444,14 +2458,14 @@
 
         /* handle "from ... import *" special b/c there's no children */
         if (TYPE(n) == STAR) {
-            alias_ty import_alias = alias_for_import_name(c, n);
+            alias_ty import_alias = alias_for_import_name(c, n, 1);
             if (!import_alias)
                 return NULL;
                 asdl_seq_SET(aliases, 0, import_alias);
         }
         else {
             for (i = 0; i < NCH(n); i += 2) {
-                alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
+                alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
                 if (!import_alias)
                     return NULL;
                     asdl_seq_SET(aliases, i / 2, import_alias);
@@ -2459,8 +2473,6 @@
         }
         if (mod != NULL)
             modname = mod->name;
-        else
-            modname = new_identifier("", c->c_arena);
         return ImportFrom(modname, aliases, ndots, lineno, col_offset,
                           c->c_arena);
     }