Refactored site.py into functions.  Also moved over to using sets.

New regression test suite.
diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
new file mode 100644
index 0000000..ee15b1e
--- /dev/null
+++ b/Lib/test/test_site.py
@@ -0,0 +1,199 @@
+"""Tests for 'site'.
+
+Tests assume the initial paths in sys.path once the interpreter has begun
+executing have not been removed.
+
+"""
+import unittest
+from test.test_support import TestSkipped, run_unittest, TESTFN
+import __builtin__
+import os
+import sys
+import encodings
+import tempfile
+# Need to make sure to not import 'site' if someone specified ``-S`` at the
+# command-line.  Detect this by just making sure 'site' has not been imported
+# already.
+if "site" in sys.modules:
+    import site
+else:
+    raise TestSkipped("importation of site.py suppressed")
+
+class HelperFunctionsTests(unittest.TestCase):
+    """Tests for helper functions.
+    
+    The setting of the encoding (set using sys.setdefaultencoding) used by
+    the Unicode implementation is not tested.
+    
+    """
+
+    def setUp(self):
+        """Save a copy of sys.path"""
+        self.sys_path = sys.path[:]
+
+    def tearDown(self):
+        """Restore sys.path"""
+        sys.path = self.sys_path
+    
+    def test_makepath(self):
+        # Test makepath() have an absolute path for its first return value
+        # and a case-normalized version of the absolute path for its
+        # second value.
+        path_parts = ("Beginning", "End")
+        original_dir = os.path.join(*path_parts)
+        abs_dir, norm_dir = site.makepath(*path_parts)
+        self.failUnlessEqual(os.path.abspath(original_dir), abs_dir)
+        if original_dir == os.path.normcase(original_dir):
+            self.failUnlessEqual(abs_dir, norm_dir)
+        else:
+            self.failUnlessEqual(os.path.normcase(abs_dir), norm_dir)
+
+    def test_init_pathinfo(self):
+        dir_set = site._init_pathinfo()
+        for entry in [site.makepath(path)[1] for path in sys.path
+                        if path and os.path.isdir(path)]:
+            self.failUnless(entry in dir_set,
+                            "%s from sys.path not found in set returned "
+                            "by _init_pathinfo(): %s" % (entry, dir_set))
+    
+    def test_addpackage(self):
+        # Make sure addpackage() imports if the line starts with 'import',
+        # otherwise add a directory combined from sitedir and 'name'.
+        # Must also skip comment lines.
+        dir_path, file_name, new_dir  = createpth()
+        try:
+            site.addpackage(dir_path, file_name, set())
+            self.failUnless(site.makepath(os.path.join(dir_path, new_dir))[0] in
+                    sys.path)
+        finally:
+            cleanuppth(dir_path, file_name, new_dir)
+    
+    def test_addsitedir(self):
+        dir_path, file_name, new_dir = createpth()
+        try:
+            site.addsitedir(dir_path, set())
+            self.failUnless(site.makepath(os.path.join(dir_path, new_dir))[0] in
+            sys.path)
+        finally:
+            cleanuppth(dir_path, file_name, new_dir)
+
+def createpth():
+    """Create a temporary .pth file at the returned location and return the
+    directory where it was created, the pth file name, and the directory
+    specified in the pth file.
+
+    Make sure to delete the file when finished.
+
+    """
+    pth_dirname = "__testdir__"
+    file_name = TESTFN + ".pth"
+    full_dirname = os.path.dirname(os.path.abspath(file_name))
+    FILE = file(os.path.join(full_dirname, file_name), 'w')
+    try:
+        print>>FILE, "#import @bad module name"
+        print>>FILE, ''
+        print>>FILE, "import os"
+        print>>FILE, pth_dirname
+    finally:
+        FILE.close()
+    os.mkdir(os.path.join(full_dirname, pth_dirname))
+    return full_dirname, file_name, pth_dirname
+
+def cleanuppth(full_dirname, file_name, pth_dirname):
+    """Clean up what createpth() made"""
+    os.remove(os.path.join(full_dirname, file_name))
+    os.rmdir(os.path.join(full_dirname, pth_dirname))
+
+class ImportSideEffectTests(unittest.TestCase):
+    """Test side-effects from importing 'site'."""
+
+    def setUp(self):
+        """Make a copy of sys.path"""
+        self.sys_path = sys.path[:]
+
+    def tearDown(self):
+        """Restore sys.path"""
+        sys.path = self.sys_path
+
+    def test_abs__file__(self):
+        # Make sure all imported modules have their __file__ attribute
+        # as an absolute path.
+        # Handled by abs__file__()
+        site.abs__file__()
+        for module in sys.modules.values():
+            try:
+                self.failUnless(os.path.isabs(module.__file__))
+            except AttributeError:
+                continue
+
+    def test_no_duplicate_paths(self):
+        # No duplicate paths should exist in sys.path
+        # Handled by removeduppaths()
+        site.removeduppaths()
+        seen_paths = set()
+        for path in sys.path:
+            self.failUnless(path not in seen_paths)
+            seen_paths.add(path)
+
+    def test_add_build_dir(self):
+        # Test that the build directory's Modules directory is used when it
+        # should be.
+        # XXX: implement
+        pass
+
+    def test_sitepackages(self):
+        # There should be a path that ends in site-packages
+        for path in sys.path:
+            if path.endswith("site-packages"):
+                break
+        else:
+            self.fail("'site-packages' directory missing'")
+
+    def test_setting_quit(self):
+        # 'quit' and 'exit' should be injected into __builtin__
+        self.failUnless(hasattr(__builtin__, "quit"))
+        self.failUnless(hasattr(__builtin__, "exit"))
+
+    def test_setting_copyright(self):
+        # 'copyright' and 'credits' should be in __builtin__
+        self.failUnless(hasattr(__builtin__, "copyright"))
+        self.failUnless(hasattr(__builtin__, "credits"))
+
+    def test_setting_help(self):
+        # 'help' should be set in __builtin__
+        self.failUnless(hasattr(__builtin__, "help"))
+
+    def test_aliasing_mbcs(self):
+        if sys.platform == "win32":
+            import locale
+            if locale.getdefaultlocale()[1].startswith('cp'):
+                for value in encodings.aliases.aliases.itervalues():
+                    if value == "mbcs":
+                        break
+                else:
+                    self.fail("did not alias mbcs")
+
+    def test_setdefaultencoding_removed(self):
+        # Make sure sys.setdefaultencoding is gone
+        self.failUnless(not hasattr(sys, "setdefaultencoding"))
+
+    def test_sitecustomize_executed(self):
+        # If sitecustomize is available, it should have been imported.
+        if not sys.modules.has_key("sitecustomize"):
+            try:
+                import sitecustomize
+            except ImportError:
+                pass
+            else:
+                self.fail("sitecustomize not imported automatically")
+
+
+
+
+def test_main():
+    run_unittest(HelperFunctionsTests, ImportSideEffectTests)
+
+
+
+if __name__ == "__main__":
+    test_main()