--- mga-gnome/trunk/mga-gnome	2012/02/24 12:26:02	3045
+++ mga-gnome/trunk/mga-gnome	2012/02/25 19:58:52	3057
@@ -1,18 +1,37 @@
 #!/usr/bin/python
 
+# A lot of the code comes from ftpadmin, see
+#   http://git.gnome.org/browse/sysadmin-bin/tree/ftpadmin
+# Written by Olav Vitters
+
+# basic modules:
 import os
 import os.path
 import sys
 import re
 import subprocess
-import urllib2
-import urlparse
+
+# command line parsing, error handling:
 import argparse
 import errno
+
+# overwriting files by moving them (safer):
 import tempfile
 import shutil
+
+# version comparison:
 import rpm
+
+# opening tarballs:
+import tarfile
+import gzip
+import bz2
+import lzma # pyliblzma
+
+# getting links from HTML document:
 from sgmllib import SGMLParser
+import urllib2
+import urlparse
 
 MEDIA="Core Release Source"
 URL="http://download.gnome.org/sources/"
@@ -84,6 +103,40 @@
         if href:
             self.urls.extend(href)
 
+class XzTarFile(tarfile.TarFile):
+
+    OPEN_METH = tarfile.TarFile.OPEN_METH.copy()
+    OPEN_METH["xz"] = "xzopen"
+
+    @classmethod
+    def xzopen(cls, name, mode="r", fileobj=None, **kwargs):
+        """Open gzip compressed tar archive name for reading or writing.
+           Appending is not allowed.
+        """
+        if len(mode) > 1 or mode not in "rw":
+            raise ValueError("mode must be 'r' or 'w'")
+
+        if fileobj is not None:
+            fileobj = _LMZAProxy(fileobj, mode)
+        else:
+            fileobj = lzma.LZMAFile(name, mode)
+
+        try:
+            # lzma doesn't immediately return an error
+            # try and read a bit of data to determine if it is a valid xz file
+            fileobj.read(_LZMAProxy.blocksize)
+            fileobj.seek(0)
+            t = cls.taropen(name, mode, fileobj, **kwargs)
+        except IOError:
+            raise tarfile.ReadError("not a xz file")
+        except lzma.error:
+            raise tarfile.ReadError("not a xz file")
+        t._extfileobj = False
+        return t
+
+if not hasattr(tarfile.TarFile, 'xvopen'):
+    tarfile.open = XzTarFile.open
+
 class SpecFile(object):
     re_update_version = re.compile(r'^(?P<pre>Version:\s*)(?P<version>.+)(?P<post>\s*)$', re.MULTILINE + re.IGNORECASE)
     re_update_release = re.compile(r'^(?P<pre>Release:\s*)(?P<release>%mkrel \d+)(?P<post>\s*)$', re.MULTILINE + re.IGNORECASE)