Index: subversion/tests/cmdline/import_tests.py
===================================================================
--- subversion/tests/cmdline/import_tests.py	(revision 25383)
+++ subversion/tests/cmdline/import_tests.py	(working copy)
@@ -25,6 +25,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = wc.StateItem
 
@@ -369,7 +370,7 @@
 
 # list all tests here, starting with None:
 test_list = [ None,
-              Skip(import_executable, svntest.main.is_non_posix_os),
+              SkipUnless(import_executable, svntest.main.is_posix_os),
               import_ignores,
               import_avoid_empty_revision,
               import_no_ignores,
Index: subversion/tests/cmdline/lock_tests.py
===================================================================
--- subversion/tests/cmdline/lock_tests.py	(revision 25383)
+++ subversion/tests/cmdline/lock_tests.py	(working copy)
@@ -27,6 +27,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -1552,8 +1553,8 @@
               lock_several_files,
               lock_switched_files,
               lock_uri_encoded,
-              Skip(lock_and_exebit1, svntest.main.is_non_posix_os),
-              Skip(lock_and_exebit2, svntest.main.is_non_posix_os),
+              SkipUnless(lock_and_exebit1, svntest.main.is_posix_os),
+              SkipUnless(lock_and_exebit2, svntest.main.is_posix_os),
               commit_xml_unsafe_file_unlock,
               repos_lock_with_info,
               unlock_already_unlocked_files,
Index: subversion/tests/cmdline/copy_tests.py
===================================================================
--- subversion/tests/cmdline/copy_tests.py	(revision 25383)
+++ subversion/tests/cmdline/copy_tests.py	(working copy)
@@ -27,6 +27,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -3689,7 +3690,8 @@
               copy_files_with_properties,
               copy_delete_commit,
               mv_and_revert_directory,
-              Skip(copy_preserve_executable_bit, svntest.main.is_non_posix_os),
+              SkipUnless(copy_preserve_executable_bit,
+                         svntest.main.is_posix_os),
               wc_to_repos,
               repos_to_wc,
               copy_to_root,
Index: subversion/tests/cmdline/stat_tests.py
===================================================================
--- subversion/tests/cmdline/stat_tests.py	(revision 25383)
+++ subversion/tests/cmdline/stat_tests.py	(working copy)
@@ -26,6 +26,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -1498,7 +1499,8 @@
               status_shows_all_in_current_dir,
               status_missing_file,
               status_type_change,
-              Skip(status_type_change_to_symlink, svntest.main.is_non_posix_os),
+              SkipUnless(status_type_change_to_symlink,
+                         svntest.main.is_posix_os),
               status_with_new_files_pending,
               status_for_unignored_file,
               status_for_nonexistent_file,
Index: subversion/tests/cmdline/special_tests.py
===================================================================
--- subversion/tests/cmdline/special_tests.py	(revision 25383)
+++ subversion/tests/cmdline/special_tests.py	(working copy)
@@ -25,6 +25,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -605,19 +606,19 @@
 
 # list all tests here, starting with None:
 test_list = [ None,
-              Skip(general_symlink, svntest.main.is_non_posix_os),
-              Skip(replace_file_with_symlink, svntest.main.is_non_posix_os),
-              Skip(import_export_symlink, svntest.main.is_non_posix_os),
-              Skip(copy_tree_with_symlink, svntest.main.is_non_posix_os),
-              Skip(replace_symlink_with_file, svntest.main.is_non_posix_os),
-              Skip(remove_symlink, svntest.main.is_non_posix_os),
-              Skip(merge_symlink_into_file, svntest.main.is_non_posix_os),
-              Skip(merge_file_into_symlink, svntest.main.is_non_posix_os),
+              SkipUnless(general_symlink, svntest.main.is_posix_os),
+              SkipUnless(replace_file_with_symlink, svntest.main.is_posix_os),
+              SkipUnless(import_export_symlink, svntest.main.is_posix_os),
+              SkipUnless(copy_tree_with_symlink, svntest.main.is_posix_os),
+              SkipUnless(replace_symlink_with_file, svntest.main.is_posix_os),
+              SkipUnless(remove_symlink, svntest.main.is_posix_os),
+              SkipUnless(merge_symlink_into_file, svntest.main.is_posix_os),
+              SkipUnless(merge_file_into_symlink, svntest.main.is_posix_os),
               checkout_repo_with_symlinks,
-              XFail(Skip(diff_symlink_to_dir, svntest.main.is_non_posix_os)),
+              XFail(SkipUnless(diff_symlink_to_dir, svntest.main.is_posix_os)),
               checkout_repo_with_unknown_special_type,
               replace_symlink_with_dir,
-              Skip(update_obstructing_symlink, svntest.main.is_non_posix_os),
+              SkipUnless(update_obstructing_symlink, svntest.main.is_posix_os),
              ]
 
 if __name__ == '__main__':
Index: subversion/tests/cmdline/prop_tests.py
===================================================================
--- subversion/tests/cmdline/prop_tests.py	(revision 25383)
+++ subversion/tests/cmdline/prop_tests.py	(working copy)
@@ -25,12 +25,13 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
 def is_non_posix_and_non_windows_os():
   """lambda function to skip revprop_change test"""
-  return svntest.main.is_non_posix_os() and sys.platform != 'win32'
+  return (not svntest.main.is_posix_os()) and sys.platform != 'win32'
 
 # Helper functions
 def check_prop(name, path, exp_out):
Index: subversion/tests/cmdline/commit_tests.py
===================================================================
--- subversion/tests/cmdline/commit_tests.py	(revision 25383)
+++ subversion/tests/cmdline/commit_tests.py	(working copy)
@@ -25,6 +25,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -34,7 +35,7 @@
 #
 
 def is_non_posix_os_or_cygwin_platform():
-  return svntest.main.is_non_posix_os() or sys.platform == 'cygwin'
+  return (not svntest.main.is_posix_os()) or sys.platform == 'cygwin'
 
 def get_standard_state(wc_dir):
   """Return a status list reflecting the local mods made by
Index: subversion/tests/cmdline/authz_tests.py
===================================================================
--- subversion/tests/cmdline/authz_tests.py	(revision 25383)
+++ subversion/tests/cmdline/authz_tests.py	(working copy)
@@ -30,6 +30,7 @@
 Item = svntest.wc.StateItem
 XFail = svntest.testcase.XFail
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 
 ######################################################################
 # Tests
@@ -815,9 +816,6 @@
 def authz_svnserve_anon_access_read(sbox):
   "authz issue #2712"
 
-  if not svntest.main.is_ra_type_svn():
-    raise svntest.Skip
-
   sbox.build(create_wc = False)
   svntest.main.safe_rmtree(sbox.wc_dir)
   B_path = os.path.join(sbox.wc_dir, 'A', 'B')
@@ -862,7 +860,8 @@
               authz_aliases,
               authz_validate,
               authz_locking,
-              authz_svnserve_anon_access_read,
+              SkipUnless(authz_svnserve_anon_access_read,
+                         svntest.main.is_ra_type_svn),
              ]
 
 if __name__ == '__main__':
Index: subversion/tests/cmdline/schedule_tests.py
===================================================================
--- subversion/tests/cmdline/schedule_tests.py	(revision 25383)
+++ subversion/tests/cmdline/schedule_tests.py	(working copy)
@@ -26,6 +26,7 @@
 
 # (abbreviation)
 Skip = svntest.testcase.Skip
+SkipUnless = svntest.testcase.SkipUnless
 XFail = svntest.testcase.XFail
 Item = svntest.wc.StateItem
 
@@ -624,7 +625,7 @@
               revert_add_files,
               revert_add_directories,
               revert_nested_adds,
-              Skip(revert_add_executable, svntest.main.is_non_posix_os),
+              SkipUnless(revert_add_executable, svntest.main.is_posix_os),
               revert_delete_files,
               revert_delete_dirs,
               unschedule_missing_added,
Index: subversion/tests/cmdline/svntest/testcase.py
===================================================================
--- subversion/tests/cmdline/svntest/testcase.py	(revision 25385)
+++ subversion/tests/cmdline/svntest/testcase.py	(working copy)
@@ -157,7 +157,7 @@
 
 
 class Skip(TestCase):
-  """A test that will be skipped if condition COND is true."""
+  """A test that will be skipped if its conditional is true."""
 
   def __init__(self, test_case, cond_func=lambda:1):
     """Create an Skip instance based on TEST_CASE.  COND_FUNC is a
@@ -173,7 +173,7 @@
     self.test_case = create_test_case(test_case)
     self.cond_func = cond_func
     try:
-      if self.cond_func():
+      if self.conditional():
         self._list_mode_text = 'SKIP'
     except svntest.Failure:
       pass
@@ -183,20 +183,36 @@
     self.convert_result = self.test_case.convert_result
 
   def need_sandbox(self):
-    if self.cond_func():
+    if self.conditional():
       return 0
     else:
       return self.test_case.need_sandbox()
 
   def run(self, sandbox=None):
-    if self.cond_func():
+    if self.conditional():
       raise svntest.Skip
     elif self.need_sandbox():
       return self.test_case.run(sandbox=sandbox)
     else:
       return self.test_case.run()
 
+  def conditional(self):
+    """Invoke SELF.cond_func(), and return the result evaluated
+    against the expected value."""
+    return self.cond_func()
 
+
+class SkipUnless(Skip):
+  """A test that will be skipped if its conditional is false."""
+
+  def __init__(self, test_case, cond_func):
+    Skip.__init__(self, test_case, cond_func)
+
+  def conditional(self):
+    "Return the negation of SELF.cond_func()."
+    return not self.cond_func()
+
+
 def create_test_case(func):
   if isinstance(func, TestCase):
     return func
Index: subversion/tests/cmdline/svntest/main.py
===================================================================
--- subversion/tests/cmdline/svntest/main.py	(revision 25383)
+++ subversion/tests/cmdline/svntest/main.py	(working copy)
@@ -667,8 +667,8 @@
 def is_os_windows():
   return (os.name == 'nt')
 
-def is_non_posix_os():
-  return (os.name != 'posix')
+def is_posix_os():
+  return (os.name == 'posix')
 
 ######################################################################
 # Sandbox handling