Tarball conversion

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diff --git a/bzrlib/inspect_for_copy.py b/bzrlib/inspect_for_copy.py
new file mode 100644
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+++ b/bzrlib/inspect_for_copy.py
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+# Copyright (C) 2005, 2006 Canonical Ltd
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+"""A version of inspect that includes what 'copy' needs.
+
+Importing the python standard module 'copy' is far more expensive than it
+needs to be, because copy imports 'inspect' which imports 'tokenize'.
+And 'copy' only needs 2 small functions out of 'inspect', but has to
+load all of 'tokenize', which makes it horribly slow.
+
+This module is designed to use tricky hacks in import rules, to avoid this
+overhead.
+"""
+
+from __future__ import absolute_import
+
+
+####
+# These are the only 2 functions that 'copy' needs from 'inspect'
+# As you can see, they are quite trivial, and don't justify the
+# 40ms spent to import 'inspect' because it is importing 'tokenize'
+# These are copied verbatim from the python standard library.
+
+# ----------------------------------------------------------- class helpers
+def _searchbases(cls, accum):
+    # Simulate the "classic class" search order.
+    if cls in accum:
+        return
+    accum.append(cls)
+    for base in cls.__bases__:
+        _searchbases(base, accum)
+
+
+def getmro(cls):
+    "Return tuple of base classes (including cls) in method resolution order."
+    if hasattr(cls, "__mro__"):
+        return cls.__mro__
+    else:
+        result = []
+        _searchbases(cls, result)
+        return tuple(result)
+
+
+def import_copy_with_hacked_inspect():
+    """Import the 'copy' module with a hacked 'inspect' module"""
+    # We don't actually care about 'getmro' but we need to pass
+    # something in the list so that we get the direct module,
+    # rather than getting the base module
+    import sys
+
+    # Don't hack around if 'inspect' already exists
+    if 'inspect' in sys.modules:
+        import copy
+        return
+
+    mod = __import__('bzrlib.inspect_for_copy',
+                     globals(), locals(), ['getmro'])
+
+    sys.modules['inspect'] = mod
+    try:
+        import copy
+    finally:
+        del sys.modules['inspect']