backport r67077 from the trunk: parser module now correctly validates relative imports

Lib/test/test_parser.py

 import parser
+import os
 import unittest
 from test import test_support
 
@@ -168,6 +169,7 @@ class RoundtripLegalSyntaxTestCase(unittest.TestCase):
             "from sys.path import (dirname, basename as my_basename)")
         self.check_suite(
             "from sys.path import (dirname, basename as my_basename,)")
+        self.check_suite("from .bogus import x")
 
     def test_basic_import_statement(self):
         self.check_suite("import sys")

Misc/ACKS

@@ -60,6 +60,7 @@ Eric Beser
 Steven Bethard
 Stephen Bevan
 Ron Bickers
+David Binger
 Dominic Binks
 Philippe Biondi
 Stuart Bishop

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.5.3?
 Core and builtins
 -----------------
 
+- Issue #4048: The parser module now correctly validates relative imports.
+
 - Issue #4176: Fixed a crash when pickling an object which ``__reduce__``
   method does not return iterators for the 4th and 5th items.
 

Modules/parsermodule.c

@@ -1804,10 +1804,10 @@ static int
 count_from_dots(node *tree)
 {
         int i;
-        for (i = 0; i < NCH(tree); i++)
+        for (i = 1; i < NCH(tree); i++)
 		if (TYPE(CHILD(tree, i)) != DOT)
 			break;
-        return i;
+        return i-1;
 }
 
 /* 'from' ('.'* dotted_name | '.') 'import' ('*' | '(' import_as_names ')' |