install.py: Python 2.6 and 3.1 optparse compat

diff --git a/bin/install.py b/bin/install.py
index 6be39002258a205478343dcbc6e5f3d360da29b6..3fdd5be3b16c15a6257d7d5466e1c7bd25869a38 100755 (executable)
--- a/bin/install.py
+++ b/bin/install.py
@@ -4,13 +4,26 @@
 
 import os
 import sys
-import argparse
 import subprocess
 import traceback
 
 from portage.util.movefile import _copyxattr
 from portage.exception import OperationNotSupported
 
+try:
+       from argparse import ArgumentParser
+except ImportError:
+       # Compatibility with Python 2.6 and 3.1
+       from optparse import OptionParser
+
+       class ArgumentParser(object):
+               def __init__(self, **kwargs):
+                       add_help = kwargs.pop("add_help", None)
+                       if add_help is not None:
+                               kwargs["add_help_option"] = add_help
+                       parser = OptionParser(**kwargs)
+                       self.add_argument = parser.add_option
+                       self.parse_known_args = parser.parse_args
 
 def parse_args(args):
        """
@@ -20,7 +33,7 @@ def parse_args(args):
        Returns:
          tuple of the Namespace of parsed options, and a list of order parameters
        """
-       parser = argparse.ArgumentParser(add_help=False)
+       parser = ArgumentParser(add_help=False)
 
        parser.add_argument(
                "-b",