Merge branch 'cygwin' of https://github.com/ankostis/GitPython into ankostis-cygwin

18 files changed, 433 insertions, 319 deletions

diff --git a/git/test/lib/helper.py b/git/test/lib/helper.py
index b009a9cd..1515f2a1 100644
--- a/git/test/lib/helper.py
+++ b/git/test/lib/helper.py
@@ -5,6 +5,7 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 from __future__ import print_function
 
+import contextlib
 from functools import wraps
 import io
 import logging
@@ -16,7 +17,7 @@ from unittest import TestCase
 import unittest
 
 from git.compat import string_types, is_win, PY3
-from git.util import rmtree
+from git.util import rmtree, cwd
 
 import os.path as osp
 
@@ -32,7 +33,7 @@ __all__ = (
     'GIT_REPO', 'GIT_DAEMON_PORT'
 )
 
-log = logging.getLogger('git.util')
+log = logging.getLogger(__name__)
 
 #{ Routines
 
@@ -118,7 +119,7 @@ def with_rw_repo(working_tree_ref, bare=False):
             if bare:
                 prefix = ''
             # END handle prefix
-            repo_dir = tempfile.mktemp("%sbare_%s" % (prefix, func.__name__))
+            repo_dir = tempfile.mktemp(prefix="%sbare_%s" % (prefix, func.__name__))
             rw_repo = self.rorepo.clone(repo_dir, shared=True, bare=bare, n=True)
 
             rw_repo.head.commit = rw_repo.commit(working_tree_ref)
@@ -151,32 +152,66 @@ def with_rw_repo(working_tree_ref, bare=False):
     return argument_passer
 
 
-def launch_git_daemon(base_path, ip, port):
-    from git import Git
-    if is_win:
-        ## On MINGW-git, daemon exists in .\Git\mingw64\libexec\git-core\,
-        #  but if invoked as 'git daemon', it detaches from parent `git` cmd,
-        #  and then CANNOT DIE!
-        #  So, invoke it as a single command.
-        ## Cygwin-git has no daemon.  But it can use MINGW's.
-        #
-        daemon_cmd = ['git-daemon',
-                      '--enable=receive-pack',
-                      '--listen=%s' % ip,
-                      '--port=%s' % port,
-                      '--base-path=%s' % base_path,
-                      base_path]
-        gd = Git().execute(daemon_cmd, as_process=True)
+@contextlib.contextmanager
+def git_daemon_launched(base_path, ip, port):
+    from git import Git  # Avoid circular deps.
+
+    gd = None
+    try:
+        if is_win:
+            ## On MINGW-git, daemon exists in .\Git\mingw64\libexec\git-core\,
+            #  but if invoked as 'git daemon', it detaches from parent `git` cmd,
+            #  and then CANNOT DIE!
+            #  So, invoke it as a single command.
+            ## Cygwin-git has no daemon.  But it can use MINGW's.
+            #
+            daemon_cmd = ['git-daemon',
+                          '--enable=receive-pack',
+                          '--listen=%s' % ip,
+                          '--port=%s' % port,
+                          '--base-path=%s' % base_path,
+                          base_path]
+            gd = Git().execute(daemon_cmd, as_process=True)
+        else:
+            gd = Git().daemon(base_path,
+                              enable='receive-pack',
+                              listen=ip,
+                              port=port,
+                              base_path=base_path,
+                              as_process=True)
+        # yes, I know ... fortunately, this is always going to work if sleep time is just large enough
+        time.sleep(0.5 * (1 + is_win))
+    except Exception as ex:
+        msg = textwrap.dedent("""
+        Launching git-daemon failed due to: %s
+          Probably test will fail subsequently.
+
+          BUT you may start *git-daemon* manually with this command:"
+                git daemon --enable=receive-pack  --listen=%s --port=%s --base-path=%s  %s
+          You may also run the daemon on a different port by passing --port=<port>"
+          and setting the environment variable GIT_PYTHON_TEST_GIT_DAEMON_PORT to <port>
+        """)
+        if is_win:
+            msg += textwrap.dedent("""
+
+            On Windows,
+              the `git-daemon.exe` must be in PATH.
+              For MINGW, look into .\Git\mingw64\libexec\git-core\), but problems with paths might appear.
+              CYGWIN has no daemon, but if one exists, it gets along fine (but has also paths problems).""")
+        log.warning(msg, ex, ip, port, base_path, base_path, exc_info=1)
+
+        yield  # OK, assume daemon started manually.
+
     else:
-        gd = Git().daemon(base_path,
-                          enable='receive-pack',
-                          listen=ip,
-                          port=port,
-                          base_path=base_path,
-                          as_process=True)
-    # yes, I know ... fortunately, this is always going to work if sleep time is just large enough
-    time.sleep(0.5)
-    return gd
+        yield  # Yield outside try, to avoid catching
+    finally:
+        if gd:
+            try:
+                log.debug("Killing git-daemon...")
+                gd.proc.kill()
+            except Exception as ex:
+                ## Either it has died (and we're here), or it won't die, again here...
+                log.debug("Hidden error while Killing git-daemon: %s", ex, exc_info=1)
 
 
 def with_rw_and_rw_remote_repo(working_tree_ref):
@@ -196,7 +231,7 @@ def with_rw_and_rw_remote_repo(working_tree_ref):
      rorepo ---<bare clone>---> rw_remote_repo ---<clone>---> rw_repo
 
     The test case needs to support the following signature::
-        def case(self, rw_repo, rw_remote_repo)
+        def case(self, rw_repo, rw_daemon_repo)
 
     This setup allows you to test push and pull scenarios and hooks nicely.
 
@@ -211,94 +246,65 @@ def with_rw_and_rw_remote_repo(working_tree_ref):
 
         @wraps(func)
         def remote_repo_creator(self):
-            remote_repo_dir = tempfile.mktemp("remote_repo_%s" % func.__name__)
-            repo_dir = tempfile.mktemp("remote_clone_non_bare_repo")
+            rw_daemon_repo_dir = tempfile.mktemp(prefix="daemon_repo-%s-" % func.__name__)
+            rw_repo_dir = tempfile.mktemp(prefix="daemon_cloned_repo-%s-" % func.__name__)
 
-            rw_remote_repo = self.rorepo.clone(remote_repo_dir, shared=True, bare=True)
+            rw_daemon_repo = self.rorepo.clone(rw_daemon_repo_dir, shared=True, bare=True)
             # recursive alternates info ?
-            rw_repo = rw_remote_repo.clone(repo_dir, shared=True, bare=False, n=True)
-            rw_repo.head.commit = working_tree_ref
-            rw_repo.head.reference.checkout()
-
-            # prepare for git-daemon
-            rw_remote_repo.daemon_export = True
-
-            # this thing is just annoying !
-            with rw_remote_repo.config_writer() as crw:
-                section = "daemon"
-                try:
-                    crw.add_section(section)
-                except Exception:
-                    pass
-                crw.set(section, "receivepack", True)
-
-            # Initialize the remote - first do it as local remote and pull, then
-            # we change the url to point to the daemon.
-            d_remote = Remote.create(rw_repo, "daemon_origin", remote_repo_dir)
-            d_remote.fetch()
-
-            base_path, rel_repo_dir = osp.split(remote_repo_dir)
-
-            remote_repo_url = Git.polish_url("git://localhost:%s/%s" % (GIT_DAEMON_PORT, rel_repo_dir))
-            with d_remote.config_writer as cw:
-                cw.set('url', remote_repo_url)
-
+            rw_repo = rw_daemon_repo.clone(rw_repo_dir, shared=True, bare=False, n=True)
             try:
-                gd = launch_git_daemon(Git.polish_url(base_path), '127.0.0.1', GIT_DAEMON_PORT)
-            except Exception as ex:
-                if is_win:
-                    msg = textwrap.dedent("""
-                    The `git-daemon.exe` must be in PATH.
-                    For MINGW, look into .\Git\mingw64\libexec\git-core\), but problems with paths might appear.
-                    CYGWIN has no daemon, but if one exists, it gets along fine (has also paths problems)
-                    Anyhow, alternatively try starting `git-daemon` manually:""")
-                else:
-                    msg = "Please try starting `git-daemon` manually:"
-                msg += textwrap.dedent("""
-                    git daemon --enable=receive-pack  --base-path=%s  %s
-                You can also run the daemon on a different port by passing --port=<port>"
-                and setting the environment variable GIT_PYTHON_TEST_GIT_DAEMON_PORT to <port>
-                """ % (base_path, base_path))
-                raise AssertionError(ex, msg)
-                # END make assertion
-            else:
-                # Try listing remotes, to diagnose whether the daemon is up.
-                rw_repo.git.ls_remote(d_remote)
-
-                # adjust working dir
-                prev_cwd = os.getcwd()
-                os.chdir(rw_repo.working_dir)
+                rw_repo.head.commit = working_tree_ref
+                rw_repo.head.reference.checkout()
 
-                try:
-                    return func(self, rw_repo, rw_remote_repo)
-                except:
-                    log.info("Keeping repos after failure: repo_dir = %s, remote_repo_dir = %s",
-                             repo_dir, remote_repo_dir)
-                    repo_dir = remote_repo_dir = None
-                    raise
-                finally:
-                    os.chdir(prev_cwd)
+                # prepare for git-daemon
+                rw_daemon_repo.daemon_export = True
+
+                # this thing is just annoying !
+                with rw_daemon_repo.config_writer() as crw:
+                    section = "daemon"
+                    try:
+                        crw.add_section(section)
+                    except Exception:
+                        pass
+                    crw.set(section, "receivepack", True)
+
+                # Initialize the remote - first do it as local remote and pull, then
+                # we change the url to point to the daemon.
+                d_remote = Remote.create(rw_repo, "daemon_origin", rw_daemon_repo_dir)
+                d_remote.fetch()
+
+                base_daemon_path, rel_repo_dir = osp.split(rw_daemon_repo_dir)
+
+                remote_repo_url = Git.polish_url("git://localhost:%s/%s" % (GIT_DAEMON_PORT, rel_repo_dir))
+                with d_remote.config_writer as cw:
+                    cw.set('url', remote_repo_url)
+
+                with git_daemon_launched(Git.polish_url(base_daemon_path, is_cygwin=False),  # No daemon in Cygwin.
+                                         '127.0.0.1',
+                                         GIT_DAEMON_PORT):
+                    # Try listing remotes, to diagnose whether the daemon is up.
+                    rw_repo.git.ls_remote(d_remote)
+
+                    with cwd(rw_repo.working_dir):
+                        try:
+                            return func(self, rw_repo, rw_daemon_repo)
+                        except:
+                            log.info("Keeping repos after failure: \n  rw_repo_dir: %s \n  rw_daemon_repo_dir: %s",
+                                     rw_repo_dir, rw_daemon_repo_dir)
+                            rw_repo_dir = rw_daemon_repo_dir = None
+                            raise
 
             finally:
-                try:
-                    log.debug("Killing git-daemon...")
-                    gd.proc.kill()
-                except:
-                    ## Either it has died (and we're here), or it won't die, again here...
-                    pass
-
                 rw_repo.git.clear_cache()
-                rw_remote_repo.git.clear_cache()
-                rw_repo = rw_remote_repo = None
+                rw_daemon_repo.git.clear_cache()
+                del rw_repo
+                del rw_daemon_repo
                 import gc
                 gc.collect()
-                if repo_dir:
-                    rmtree(repo_dir)
-                if remote_repo_dir:
-                    rmtree(remote_repo_dir)
-
-                if gd is not None:
-                    gd.proc.wait()
+                if rw_repo_dir:
+                    rmtree(rw_repo_dir)
+                if rw_daemon_repo_dir:
+                    rmtree(rw_daemon_repo_dir)
             # END cleanup
         # END bare repo creator
         return remote_repo_creator
diff --git a/git/test/performance/lib.py b/git/test/performance/lib.py
index ed82e4dd..7edffa78 100644
--- a/git/test/performance/lib.py
+++ b/git/test/performance/lib.py
@@ -1,22 +1,23 @@
 """Contains library functions"""
+import logging
 import os
-from git.test.lib import (
-    TestBase
-)
 import tempfile
-import logging
 
+from git import (
+    Repo
+)
 from git.db import (
     GitCmdObjectDB,
     GitDB
 )
-
-from git import (
-    Repo
+from git.test.lib import (
+    TestBase
 )
 from git.util import rmtree
+import os.path as osp
 
 #{ Invariants
+
 k_env_git_repo = "GIT_PYTHON_TEST_GIT_REPO_BASE"
 
 #} END invariants
@@ -52,7 +53,7 @@ class TestBigRepoR(TestBase):
             logging.info(
                 ("You can set the %s environment variable to a .git repository of" % k_env_git_repo) +
                 "your choice - defaulting to the gitpython repository")
-            repo_path = os.path.dirname(__file__)
+            repo_path = osp.dirname(__file__)
         # end set some repo path
         self.gitrorepo = Repo(repo_path, odbt=GitCmdObjectDB, search_parent_directories=True)
         self.puregitrorepo = Repo(repo_path, odbt=GitDB, search_parent_directories=True)
diff --git a/git/test/performance/test_streams.py b/git/test/performance/test_streams.py
index 42cbade5..3909d8ff 100644
--- a/git/test/performance/test_streams.py
+++ b/git/test/performance/test_streams.py
@@ -1,26 +1,27 @@
 """Performance data streaming performance"""
 from __future__ import print_function
 
-from time import time
 import os
-import sys
 import subprocess
+import sys
+from time import time
 
 from git.test.lib import (
     with_rw_repo
 )
-from gitdb.util import bin_to_hex
+from git.util import bin_to_hex
+from gitdb import (
+    LooseObjectDB,
+    IStream
+)
 from gitdb.test.lib import make_memory_file
 
+import os.path as osp
+
 from .lib import (
     TestBigRepoR
 )
 
-from gitdb import (
-    LooseObjectDB,
-    IStream
-)
-
 
 class TestObjDBPerformance(TestBigRepoR):
 
@@ -31,7 +32,7 @@ class TestObjDBPerformance(TestBigRepoR):
     def test_large_data_streaming(self, rwrepo):
         # TODO: This part overlaps with the same file in gitdb.test.performance.test_stream
         # It should be shared if possible
-        ldb = LooseObjectDB(os.path.join(rwrepo.git_dir, 'objects'))
+        ldb = LooseObjectDB(osp.join(rwrepo.git_dir, 'objects'))
 
         for randomize in range(2):
             desc = (randomize and 'random ') or ''
@@ -47,7 +48,7 @@ class TestObjDBPerformance(TestBigRepoR):
             elapsed_add = time() - st
             assert ldb.has_object(binsha)
             db_file = ldb.readable_db_object_path(bin_to_hex(binsha))
-            fsize_kib = os.path.getsize(db_file) / 1000
+            fsize_kib = osp.getsize(db_file) / 1000
 
             size_kib = size / 1000
             msg = "Added %i KiB (filesize = %i KiB) of %s data to loose odb in %f s ( %f Write KiB / s)"
@@ -109,7 +110,7 @@ class TestObjDBPerformance(TestBigRepoR):
             assert gitsha == bin_to_hex(binsha)     # we do it the same way, right ?
 
             #  as its the same sha, we reuse our path
-            fsize_kib = os.path.getsize(db_file) / 1000
+            fsize_kib = osp.getsize(db_file) / 1000
             msg = "Added %i KiB (filesize = %i KiB) of %s data to using git-hash-object in %f s ( %f Write KiB / s)"
             msg %= (size_kib, fsize_kib, desc, gelapsed_add, size_kib / gelapsed_add)
             print(msg, file=sys.stderr)
diff --git a/git/test/test_base.py b/git/test/test_base.py
index 7fc3096f..cec40de8 100644
--- a/git/test/test_base.py
+++ b/git/test/test_base.py
@@ -9,22 +9,24 @@ import sys
 import tempfile
 from unittest import skipIf
 
-import git.objects.base as base
-from git.test.lib import (
-    TestBase,
-    assert_raises,
-    with_rw_repo,
-    with_rw_and_rw_remote_repo
-)
 from git import (
     Blob,
     Tree,
     Commit,
     TagObject
 )
-from git.objects.util import get_object_type_by_name
-from gitdb.util import hex_to_bin
 from git.compat import is_win
+from git.objects.util import get_object_type_by_name
+from git.test.lib import (
+    TestBase,
+    assert_raises,
+    with_rw_repo,
+    with_rw_and_rw_remote_repo
+)
+from git.util import hex_to_bin
+
+import git.objects.base as base
+import os.path as osp
 
 
 class TestBase(TestBase):
@@ -103,19 +105,19 @@ class TestBase(TestBase):
     @with_rw_repo('HEAD', bare=True)
     def test_with_bare_rw_repo(self, bare_rw_repo):
         assert bare_rw_repo.config_reader("repository").getboolean("core", "bare")
-        assert os.path.isfile(os.path.join(bare_rw_repo.git_dir, 'HEAD'))
+        assert osp.isfile(osp.join(bare_rw_repo.git_dir, 'HEAD'))
 
     @with_rw_repo('0.1.6')
     def test_with_rw_repo(self, rw_repo):
         assert not rw_repo.config_reader("repository").getboolean("core", "bare")
-        assert os.path.isdir(os.path.join(rw_repo.working_tree_dir, 'lib'))
+        assert osp.isdir(osp.join(rw_repo.working_tree_dir, 'lib'))
 
     #@skipIf(HIDE_WINDOWS_FREEZE_ERRORS, "FIXME: Freezes!  sometimes...")
     @with_rw_and_rw_remote_repo('0.1.6')
     def test_with_rw_remote_and_rw_repo(self, rw_repo, rw_remote_repo):
         assert not rw_repo.config_reader("repository").getboolean("core", "bare")
         assert rw_remote_repo.config_reader("repository").getboolean("core", "bare")
-        assert os.path.isdir(os.path.join(rw_repo.working_tree_dir, 'lib'))
+        assert osp.isdir(osp.join(rw_repo.working_tree_dir, 'lib'))
 
     @skipIf(sys.version_info < (3,) and is_win,
             "Unicode woes, see https://github.com/gitpython-developers/GitPython/pull/519")
@@ -123,7 +125,7 @@ class TestBase(TestBase):
     def test_add_unicode(self, rw_repo):
         filename = u"שלום.txt"
 
-        file_path = os.path.join(rw_repo.working_dir, filename)
+        file_path = osp.join(rw_repo.working_dir, filename)
 
         # verify first that we could encode file name in this environment
         try:
diff --git a/git/test/test_commit.py b/git/test/test_commit.py
index fd9777fb..fbb1c244 100644
--- a/git/test/test_commit.py
+++ b/git/test/test_commit.py
@@ -6,34 +6,36 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 from __future__ import print_function
 
-from git.test.lib import (
-    TestBase,
-    assert_equal,
-    assert_not_equal,
-    with_rw_repo,
-    fixture_path,
-    StringProcessAdapter
-)
+from datetime import datetime
+from io import BytesIO
+import re
+import sys
+import time
+
 from git import (
     Commit,
     Actor,
 )
-from gitdb import IStream
-from git.test.lib import with_rw_directory
+from git import Repo
 from git.compat import (
     string_types,
     text_type
 )
-from git import Repo
+from git.objects.util import tzoffset, utc
 from git.repo.fun import touch
+from git.test.lib import (
+    TestBase,
+    assert_equal,
+    assert_not_equal,
+    with_rw_repo,
+    fixture_path,
+    StringProcessAdapter
+)
+from git.test.lib import with_rw_directory
+from gitdb import IStream
+
+import os.path as osp
 
-from io import BytesIO
-import time
-import sys
-import re
-import os
-from datetime import datetime
-from git.objects.util import tzoffset, utc
 
 try:
     from unittest.mock import Mock
@@ -232,8 +234,8 @@ class TestCommit(TestBase):
 
     @with_rw_directory
     def test_ambiguous_arg_iteration(self, rw_dir):
-        rw_repo = Repo.init(os.path.join(rw_dir, 'test_ambiguous_arg'))
-        path = os.path.join(rw_repo.working_tree_dir, 'master')
+        rw_repo = Repo.init(osp.join(rw_dir, 'test_ambiguous_arg'))
+        path = osp.join(rw_repo.working_tree_dir, 'master')
         touch(path)
         rw_repo.index.add([path])
         rw_repo.index.commit('initial commit')
diff --git a/git/test/test_config.py b/git/test/test_config.py
index 32873f24..0dfadda6 100644
--- a/git/test/test_config.py
+++ b/git/test/test_config.py
@@ -6,7 +6,6 @@
 
 import glob
 import io
-import os
 
 from git import (
     GitConfigParser
@@ -91,7 +90,7 @@ class TestBase(TestCase):
 
     @with_rw_directory
     def test_lock_reentry(self, rw_dir):
-        fpl = os.path.join(rw_dir, 'l')
+        fpl = osp.join(rw_dir, 'l')
         gcp = GitConfigParser(fpl, read_only=False)
         with gcp as cw:
             cw.set_value('include', 'some_value', 'a')
@@ -103,7 +102,7 @@ class TestBase(TestCase):
                 GitConfigParser(fpl, read_only=False)
         # but work when the lock is removed
         with GitConfigParser(fpl, read_only=False):
-            assert os.path.exists(fpl)
+            assert osp.exists(fpl)
             # reentering with an existing lock must fail due to exclusive access
             with self.assertRaises(IOError):
                 gcp.__enter__()
@@ -178,17 +177,17 @@ class TestBase(TestCase):
         # end
 
         # PREPARE CONFIG FILE A
-        fpa = os.path.join(rw_dir, 'a')
+        fpa = osp.join(rw_dir, 'a')
         with GitConfigParser(fpa, read_only=False) as cw:
             write_test_value(cw, 'a')
 
-            fpb = os.path.join(rw_dir, 'b')
-            fpc = os.path.join(rw_dir, 'c')
+            fpb = osp.join(rw_dir, 'b')
+            fpc = osp.join(rw_dir, 'c')
             cw.set_value('include', 'relative_path_b', 'b')
             cw.set_value('include', 'doesntexist', 'foobar')
             cw.set_value('include', 'relative_cycle_a_a', 'a')
             cw.set_value('include', 'absolute_cycle_a_a', fpa)
-        assert os.path.exists(fpa)
+        assert osp.exists(fpa)
 
         # PREPARE CONFIG FILE B
         with GitConfigParser(fpb, read_only=False) as cw:
diff --git a/git/test/test_db.py b/git/test/test_db.py
index 5dcf592a..8f67dd48 100644
--- a/git/test/test_db.py
+++ b/git/test/test_db.py
@@ -3,17 +3,18 @@
 #
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
-from git.test.lib import TestBase
 from git.db import GitCmdObjectDB
-from gitdb.util import bin_to_hex
 from git.exc import BadObject
-import os
+from git.test.lib import TestBase
+from git.util import bin_to_hex
+
+import os.path as osp
 
 
 class TestDB(TestBase):
 
     def test_base(self):
-        gdb = GitCmdObjectDB(os.path.join(self.rorepo.git_dir, 'objects'), self.rorepo.git)
+        gdb = GitCmdObjectDB(osp.join(self.rorepo.git_dir, 'objects'), self.rorepo.git)
 
         # partial to complete - works with everything
         hexsha = bin_to_hex(gdb.partial_to_complete_sha_hex("0.1.6"))
diff --git a/git/test/test_diff.py b/git/test/test_diff.py
index d34d84e3..48a5a641 100644
--- a/git/test/test_diff.py
+++ b/git/test/test_diff.py
@@ -4,8 +4,15 @@
 #
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
-import os
-
+import ddt
+from git import (
+    Repo,
+    GitCommandError,
+    Diff,
+    DiffIndex,
+    NULL_TREE,
+)
+from git.cmd import Git
 from git.test.lib import (
     TestBase,
     StringProcessAdapter,
@@ -14,17 +21,9 @@ from git.test.lib import (
     assert_true,
 
 )
-
 from git.test.lib import with_rw_directory
 
-from git import (
-    Repo,
-    GitCommandError,
-    Diff,
-    DiffIndex,
-    NULL_TREE,
-)
-import ddt
+import os.path as osp
 
 
 @ddt.ddt
@@ -53,10 +52,10 @@ class TestDiff(TestBase):
     def test_diff_with_staged_file(self, rw_dir):
         # SETUP INDEX WITH MULTIPLE STAGES
         r = Repo.init(rw_dir)
-        fp = os.path.join(rw_dir, 'hello.txt')
+        fp = osp.join(rw_dir, 'hello.txt')
         with open(fp, 'w') as fs:
             fs.write("hello world")
-        r.git.add(fp)
+        r.git.add(Git.polish_url(fp))
         r.git.commit(message="init")
 
         with open(fp, 'w') as fs:
diff --git a/git/test/test_docs.py b/git/test/test_docs.py
index f3c75f79..bb937d93 100644
--- a/git/test/test_docs.py
+++ b/git/test/test_docs.py
@@ -9,6 +9,8 @@ import os
 from git.test.lib import TestBase
 from git.test.lib.helper import with_rw_directory
 
+import os.path as osp
+
 
 class Tutorials(TestBase):
 
@@ -23,7 +25,7 @@ class Tutorials(TestBase):
     def test_init_repo_object(self, rw_dir):
         # [1-test_init_repo_object]
         from git import Repo
-        join = os.path.join
+        join = osp.join
 
         # rorepo is a Repo instance pointing to the git-python repository.
         # For all you know, the first argument to Repo is a path to the repository
@@ -62,7 +64,7 @@ class Tutorials(TestBase):
 
         # repository paths
         # [7-test_init_repo_object]
-        assert os.path.isdir(cloned_repo.working_tree_dir)                   # directory with your work files
+        assert osp.isdir(cloned_repo.working_tree_dir)                   # directory with your work files
         assert cloned_repo.git_dir.startswith(cloned_repo.working_tree_dir)  # directory containing the git repository
         assert bare_repo.working_tree_dir is None                            # bare repositories have no working tree
         # ![7-test_init_repo_object]
@@ -146,7 +148,7 @@ class Tutorials(TestBase):
         self.assertEqual(new_branch.checkout(), cloned_repo.active_branch)     # checking out branch adjusts the wtree
         self.assertEqual(new_branch.commit, past.commit)                       # Now the past is checked out
 
-        new_file_path = os.path.join(cloned_repo.working_tree_dir, 'my-new-file')
+        new_file_path = osp.join(cloned_repo.working_tree_dir, 'my-new-file')
         open(new_file_path, 'wb').close()                             # create new file in working tree
         cloned_repo.index.add([new_file_path])                        # add it to the index
         # Commit the changes to deviate masters history
@@ -162,7 +164,7 @@ class Tutorials(TestBase):
         # now new_branch is ahead of master, which probably should be checked out and reset softly.
         # note that all these operations didn't touch the working tree, as we managed it ourselves.
         # This definitely requires you to know what you are doing :) !
-        assert os.path.basename(new_file_path) in new_branch.commit.tree  # new file is now in tree
+        assert osp.basename(new_file_path) in new_branch.commit.tree  # new file is now in tree
         master.commit = new_branch.commit            # let master point to most recent commit
         cloned_repo.head.reference = master          # we adjusted just the reference, not the working tree or index
         # ![13-test_init_repo_object]
@@ -192,7 +194,7 @@ class Tutorials(TestBase):
     def test_references_and_objects(self, rw_dir):
         # [1-test_references_and_objects]
         import git
-        repo = git.Repo.clone_from(self._small_repo_url(), os.path.join(rw_dir, 'repo'), branch='master')
+        repo = git.Repo.clone_from(self._small_repo_url(), osp.join(rw_dir, 'repo'), branch='master')
 
         heads = repo.heads
         master = heads.master       # lists can be accessed by name for convenience
@@ -264,7 +266,7 @@ class Tutorials(TestBase):
 
         # [11-test_references_and_objects]
         hct.blobs[0].data_stream.read()        # stream object to read data from
-        hct.blobs[0].stream_data(open(os.path.join(rw_dir, 'blob_data'), 'wb'))  # write data to given stream
+        hct.blobs[0].stream_data(open(osp.join(rw_dir, 'blob_data'), 'wb'))  # write data to given stream
         # ![11-test_references_and_objects]
 
         # [12-test_references_and_objects]
@@ -350,11 +352,11 @@ class Tutorials(TestBase):
         # Access blob objects
         for (path, stage), entry in index.entries.items():  # @UnusedVariable
             pass
-        new_file_path = os.path.join(repo.working_tree_dir, 'new-file-name')
+        new_file_path = osp.join(repo.working_tree_dir, 'new-file-name')
         open(new_file_path, 'w').close()
         index.add([new_file_path])                                             # add a new file to the index
         index.remove(['LICENSE'])                                              # remove an existing one
-        assert os.path.isfile(os.path.join(repo.working_tree_dir, 'LICENSE'))  # working tree is untouched
+        assert osp.isfile(osp.join(repo.working_tree_dir, 'LICENSE'))  # working tree is untouched
 
         self.assertEqual(index.commit("my commit message").type, 'commit')              # commit changed index
         repo.active_branch.commit = repo.commit('HEAD~1')                      # forget last commit
@@ -373,11 +375,11 @@ class Tutorials(TestBase):
         # merge two trees three-way into memory
         merge_index = IndexFile.from_tree(repo, 'HEAD~10', 'HEAD', repo.merge_base('HEAD~10', 'HEAD'))
         # and persist it
-        merge_index.write(os.path.join(rw_dir, 'merged_index'))
+        merge_index.write(osp.join(rw_dir, 'merged_index'))
         # ![24-test_references_and_objects]
 
         # [25-test_references_and_objects]
-        empty_repo = git.Repo.init(os.path.join(rw_dir, 'empty'))
+        empty_repo = git.Repo.init(osp.join(rw_dir, 'empty'))
         origin = empty_repo.create_remote('origin', repo.remotes.origin.url)
         assert origin.exists()
         assert origin == empty_repo.remotes.origin == empty_repo.remotes['origin']
@@ -480,8 +482,8 @@ class Tutorials(TestBase):
     def test_add_file_and_commit(self, rw_dir):
         import git
 
-        repo_dir = os.path.join(rw_dir, 'my-new-repo')
-        file_name = os.path.join(repo_dir, 'new-file')
+        repo_dir = osp.join(rw_dir, 'my-new-repo')
+        file_name = osp.join(repo_dir, 'new-file')
 
         r = git.Repo.init(repo_dir)
         # This function just creates an empty file ...
diff --git a/git/test/test_fun.py b/git/test/test_fun.py
index 02f338dd..9d436653 100644
--- a/git/test/test_fun.py
+++ b/git/test/test_fun.py
@@ -1,6 +1,11 @@
-from git.test.lib import (
-    TestBase,
-    with_rw_repo
+from io import BytesIO
+from stat import S_IFDIR, S_IFREG, S_IFLNK
+from unittest.case import skipIf
+
+from git.compat import PY3
+from git.index import IndexFile
+from git.index.fun import (
+    aggressive_tree_merge
 )
 from git.objects.fun import (
     traverse_tree_recursive,
@@ -8,25 +13,13 @@ from git.objects.fun import (
     tree_to_stream,
     tree_entries_from_data
 )
-
-from git.index.fun import (
-    aggressive_tree_merge
+from git.test.lib import (
+    TestBase,
+    with_rw_repo
 )
-
-from gitdb.util import bin_to_hex
+from git.util import bin_to_hex
 from gitdb.base import IStream
 from gitdb.typ import str_tree_type
-from git.compat import PY3
-
-from unittest.case import skipIf
-from stat import (
-    S_IFDIR,
-    S_IFREG,
-    S_IFLNK
-)
-
-from git.index import IndexFile
-from io import BytesIO
 
 
 class TestFun(TestBase):
@@ -262,7 +255,7 @@ class TestFun(TestBase):
     def test_tree_entries_from_data_with_failing_name_decode_py2(self):
         r = tree_entries_from_data(b'100644 \x9f\0aaa')
         assert r == [('aaa', 33188, u'\udc9f')], r
-        
+
     @skipIf(not PY3, 'odd types returned ... maybe figure it out one day')
     def test_tree_entries_from_data_with_failing_name_decode_py3(self):
         r = tree_entries_from_data(b'100644 \x9f\0aaa')
diff --git a/git/test/test_git.py b/git/test/test_git.py
index 14c70e18..f97f8130 100644
--- a/git/test/test_git.py
+++ b/git/test/test_git.py
@@ -5,9 +5,17 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 import os
-import sys
 import subprocess
+import sys
 
+from git import (
+    Git,
+    GitCommandError,
+    GitCommandNotFound,
+    Repo,
+    cmd
+)
+from git.compat import PY3, is_darwin
 from git.test.lib import (
     TestBase,
     patch,
@@ -17,18 +25,12 @@ from git.test.lib import (
     assert_match,
     fixture_path
 )
-from git import (
-    Git,
-    GitCommandError,
-    GitCommandNotFound,
-    Repo,
-    cmd
-)
 from git.test.lib import with_rw_directory
-
-from git.compat import PY3, is_darwin
 from git.util import finalize_process
 
+import os.path as osp
+
+
 try:
     from unittest import mock
 except ImportError:
@@ -147,7 +149,7 @@ class TestGit(TestBase):
         exc = GitCommandNotFound
         try:
             # set it to something that doens't exist, assure it raises
-            type(self.git).GIT_PYTHON_GIT_EXECUTABLE = os.path.join(
+            type(self.git).GIT_PYTHON_GIT_EXECUTABLE = osp.join(
                 "some", "path", "which", "doesn't", "exist", "gitbinary")
             self.failUnlessRaises(exc, self.git.version)
         finally:
@@ -212,13 +214,13 @@ class TestGit(TestBase):
         self.assertEqual(new_env, {'VARKEY': 'VARVALUE'})
         self.assertEqual(self.git.environment(), {})
 
-        path = os.path.join(rw_dir, 'failing-script.sh')
+        path = osp.join(rw_dir, 'failing-script.sh')
         with open(path, 'wt') as stream:
             stream.write("#!/usr/bin/env sh\n"
                          "echo FOO\n")
         os.chmod(path, 0o777)
 
-        rw_repo = Repo.init(os.path.join(rw_dir, 'repo'))
+        rw_repo = Repo.init(osp.join(rw_dir, 'repo'))
         remote = rw_repo.create_remote('ssh-origin', "ssh://git@server/foo")
 
         with rw_repo.git.custom_environment(GIT_SSH=path):
diff --git a/git/test/test_index.py b/git/test/test_index.py
index d851743e..1abe22f4 100644
--- a/git/test/test_index.py
+++ b/git/test/test_index.py
@@ -26,7 +26,7 @@ from git import (
     GitCommandError,
     CheckoutError,
 )
-from git.compat import string_types, is_win
+from git.compat import string_types, is_win, PY3
 from git.exc import (
     HookExecutionError,
     InvalidGitRepositoryError
@@ -43,11 +43,13 @@ from git.test.lib import (
     fixture,
     with_rw_repo
 )
-from git.util import HIDE_WINDOWS_KNOWN_ERRORS
 from git.test.lib import with_rw_directory
 from git.util import Actor, rmtree
+from git.util import HIDE_WINDOWS_KNOWN_ERRORS, hex_to_bin
 from gitdb.base import IStream
-from gitdb.util import hex_to_bin
+
+import os.path as osp
+from git.cmd import Git
 
 
 class TestIndex(TestBase):
@@ -85,7 +87,7 @@ class TestIndex(TestBase):
     def _assert_entries(self, entries):
         for entry in entries:
             assert isinstance(entry, BaseIndexEntry)
-            assert not os.path.isabs(entry.path)
+            assert not osp.isabs(entry.path)
             assert "\\" not in entry.path
         # END for each entry
 
@@ -329,7 +331,7 @@ class TestIndex(TestBase):
 
         # reset the working copy as well to current head,to pull 'back' as well
         new_data = b"will be reverted"
-        file_path = os.path.join(rw_repo.working_tree_dir, "CHANGES")
+        file_path = osp.join(rw_repo.working_tree_dir, "CHANGES")
         with open(file_path, "wb") as fp:
             fp.write(new_data)
         index.reset(rev_head_parent, working_tree=True)
@@ -340,26 +342,26 @@ class TestIndex(TestBase):
             assert fp.read() != new_data
 
         # test full checkout
-        test_file = os.path.join(rw_repo.working_tree_dir, "CHANGES")
+        test_file = osp.join(rw_repo.working_tree_dir, "CHANGES")
         with open(test_file, 'ab') as fd:
             fd.write(b"some data")
         rval = index.checkout(None, force=True, fprogress=self._fprogress)
         assert 'CHANGES' in list(rval)
         self._assert_fprogress([None])
-        assert os.path.isfile(test_file)
+        assert osp.isfile(test_file)
 
         os.remove(test_file)
         rval = index.checkout(None, force=False, fprogress=self._fprogress)
         assert 'CHANGES' in list(rval)
         self._assert_fprogress([None])
-        assert os.path.isfile(test_file)
+        assert osp.isfile(test_file)
 
         # individual file
         os.remove(test_file)
         rval = index.checkout(test_file, fprogress=self._fprogress)
         self.assertEqual(list(rval)[0], 'CHANGES')
         self._assert_fprogress([test_file])
-        assert os.path.exists(test_file)
+        assert osp.exists(test_file)
 
         # checking out non-existing file throws
         self.failUnlessRaises(CheckoutError, index.checkout, "doesnt_exist_ever.txt.that")
@@ -373,7 +375,7 @@ class TestIndex(TestBase):
             index.checkout(test_file)
         except CheckoutError as e:
             self.assertEqual(len(e.failed_files), 1)
-            self.assertEqual(e.failed_files[0], os.path.basename(test_file))
+            self.assertEqual(e.failed_files[0], osp.basename(test_file))
             self.assertEqual(len(e.failed_files), len(e.failed_reasons))
             self.assertIsInstance(e.failed_reasons[0], string_types)
             self.assertEqual(len(e.valid_files), 0)
@@ -388,7 +390,7 @@ class TestIndex(TestBase):
         assert not open(test_file, 'rb').read().endswith(append_data)
 
         # checkout directory
-        rmtree(os.path.join(rw_repo.working_tree_dir, "lib"))
+        rmtree(osp.join(rw_repo.working_tree_dir, "lib"))
         rval = index.checkout('lib')
         assert len(list(rval)) > 1
 
@@ -399,11 +401,17 @@ class TestIndex(TestBase):
         existing = 0
         basedir = repo.working_tree_dir
         for f in files:
-            existing += os.path.isfile(os.path.join(basedir, f))
+            existing += osp.isfile(osp.join(basedir, f))
         # END for each deleted file
         return existing
     # END num existing helper
 
+    @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and Git.is_cygwin(),
+            """FIXME: File "C:\projects\gitpython\git\test\test_index.py", line 642, in test_index_mutation
+                self.assertEqual(fd.read(), link_target)
+                AssertionError: '!<symlink>\xff\xfe/\x00e\x00t\x00c\x00/\x00t\x00h\x00a\x00t\x00\x00\x00'
+                != '/etc/that'
+                """)
     @with_rw_repo('0.1.6')
     def test_index_mutation(self, rw_repo):
         index = rw_repo.index
@@ -458,7 +466,7 @@ class TestIndex(TestBase):
         self.failUnlessRaises(TypeError, index.remove, [1])
 
         # absolute path
-        deleted_files = index.remove([os.path.join(rw_repo.working_tree_dir, "lib")], r=True)
+        deleted_files = index.remove([osp.join(rw_repo.working_tree_dir, "lib")], r=True)
         assert len(deleted_files) > 1
         self.failUnlessRaises(ValueError, index.remove, ["/doesnt/exists"])
 
@@ -525,9 +533,9 @@ class TestIndex(TestBase):
         # re-add all files in lib
         # get the lib folder back on disk, but get an index without it
         index.reset(new_commit.parents[0], working_tree=True).reset(new_commit, working_tree=False)
-        lib_file_path = os.path.join("lib", "git", "__init__.py")
+        lib_file_path = osp.join("lib", "git", "__init__.py")
         assert (lib_file_path, 0) not in index.entries
-        assert os.path.isfile(os.path.join(rw_repo.working_tree_dir, lib_file_path))
+        assert osp.isfile(osp.join(rw_repo.working_tree_dir, lib_file_path))
 
         # directory
         entries = index.add(['lib'], fprogress=self._fprogress_add)
@@ -536,14 +544,14 @@ class TestIndex(TestBase):
         assert len(entries) > 1
 
         # glob
-        entries = index.reset(new_commit).add([os.path.join('lib', 'git', '*.py')], fprogress=self._fprogress_add)
+        entries = index.reset(new_commit).add([osp.join('lib', 'git', '*.py')], fprogress=self._fprogress_add)
         self._assert_entries(entries)
         self._assert_fprogress(entries)
         self.assertEqual(len(entries), 14)
 
         # same file
         entries = index.reset(new_commit).add(
-            [os.path.join(rw_repo.working_tree_dir, 'lib', 'git', 'head.py')] * 2, fprogress=self._fprogress_add)
+            [osp.join(rw_repo.working_tree_dir, 'lib', 'git', 'head.py')] * 2, fprogress=self._fprogress_add)
         self._assert_entries(entries)
         self.assertEqual(entries[0].mode & 0o644, 0o644)
         # would fail, test is too primitive to handle this case
@@ -583,7 +591,7 @@ class TestIndex(TestBase):
             for target in ('/etc/nonexisting', '/etc/passwd', '/etc'):
                 basename = "my_real_symlink"
 
-                link_file = os.path.join(rw_repo.working_tree_dir, basename)
+                link_file = osp.join(rw_repo.working_tree_dir, basename)
                 os.symlink(target, link_file)
                 entries = index.reset(new_commit).add([link_file], fprogress=self._fprogress_add)
                 self._assert_entries(entries)
@@ -645,7 +653,7 @@ class TestIndex(TestBase):
         # TEST RENAMING
         def assert_mv_rval(rval):
             for source, dest in rval:
-                assert not os.path.exists(source) and os.path.exists(dest)
+                assert not osp.exists(source) and osp.exists(dest)
             # END for each renamed item
         # END move assertion utility
 
@@ -661,7 +669,7 @@ class TestIndex(TestBase):
         paths = ['LICENSE', 'VERSION', 'doc']
         rval = index.move(paths, dry_run=True)
         self.assertEqual(len(rval), 2)
-        assert os.path.exists(paths[0])
+        assert osp.exists(paths[0])
 
         # again, no dry run
         rval = index.move(paths)
@@ -719,8 +727,8 @@ class TestIndex(TestBase):
         index.add(files, write=True)
         if is_win:
             hp = hook_path('pre-commit', index.repo.git_dir)
-            hpd = os.path.dirname(hp)
-            if not os.path.isdir(hpd):
+            hpd = osp.dirname(hp)
+            if not osp.isdir(hpd):
                 os.mkdir(hpd)
             with open(hp, "wt") as fp:
                 fp.write("#!/usr/bin/env sh\necho stdout; echo stderr 1>&2; exit 1")
@@ -766,7 +774,7 @@ class TestIndex(TestBase):
         for fkey in keys:
             assert fkey in index.entries
         for absfile in absfiles:
-            assert os.path.isfile(absfile)
+            assert osp.isfile(absfile)
 
     @with_rw_repo('HEAD')
     def test_compare_write_tree(self, rw_repo):
@@ -815,21 +823,21 @@ class TestIndex(TestBase):
 
         # Adding using a path should still require a non-bare repository.
         asserted = False
-        path = os.path.join('git', 'test', 'test_index.py')
+        path = osp.join('git', 'test', 'test_index.py')
         try:
             rw_bare_repo.index.add([path])
         except InvalidGitRepositoryError:
             asserted = True
         assert asserted, "Adding using a filename is not correctly asserted."
 
-    @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and sys.version_info[:2] == (2, 7), r"""
+    @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and not PY3, r"""
         FIXME:  File "C:\projects\gitpython\git\util.py", line 125, in to_native_path_linux
         return path.replace('\\', '/')
         UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 0: ordinal not in range(128)""")
     @with_rw_directory
     def test_add_utf8P_path(self, rw_dir):
         # NOTE: fp is not a Unicode object in python 2 (which is the source of the problem)
-        fp = os.path.join(rw_dir, 'ø.txt')
+        fp = osp.join(rw_dir, 'ø.txt')
         with open(fp, 'wb') as fs:
             fs.write(u'content of ø'.encode('utf-8'))
 
@@ -840,7 +848,7 @@ class TestIndex(TestBase):
     @with_rw_directory
     def test_add_a_file_with_wildcard_chars(self, rw_dir):
         # see issue #407
-        fp = os.path.join(rw_dir, '[.exe')
+        fp = osp.join(rw_dir, '[.exe')
         with open(fp, "wb") as f:
             f.write(b'something')
 
diff --git a/git/test/test_reflog.py b/git/test/test_reflog.py
index dffedf3b..20495be1 100644
--- a/git/test/test_reflog.py
+++ b/git/test/test_reflog.py
@@ -1,17 +1,18 @@
-from git.test.lib import (
-    TestBase,
-    fixture_path
-)
+import os
+import tempfile
+
 from git.objects import IndexObject
 from git.refs import (
     RefLogEntry,
     RefLog
 )
-from git.util import Actor, rmtree
-from gitdb.util import hex_to_bin
+from git.test.lib import (
+    TestBase,
+    fixture_path
+)
+from git.util import Actor, rmtree, hex_to_bin
 
-import tempfile
-import os
+import os.path as osp
 
 
 class TestRefLog(TestBase):
@@ -42,7 +43,7 @@ class TestRefLog(TestBase):
         os.mkdir(tdir)
 
         rlp_master_ro = RefLog.path(self.rorepo.head)
-        assert os.path.isfile(rlp_master_ro)
+        assert osp.isfile(rlp_master_ro)
 
         # simple read
         reflog = RefLog.from_file(rlp_master_ro)
@@ -70,7 +71,7 @@ class TestRefLog(TestBase):
         cr = self.rorepo.config_reader()
         for rlp in (rlp_head, rlp_master):
             reflog = RefLog.from_file(rlp)
-            tfile = os.path.join(tdir, os.path.basename(rlp))
+            tfile = osp.join(tdir, osp.basename(rlp))
             reflog.to_file(tfile)
             assert reflog.write() is reflog
 
diff --git a/git/test/test_refs.py b/git/test/test_refs.py
index 43f1dcc7..fd0be108 100644
--- a/git/test/test_refs.py
+++ b/git/test/test_refs.py
@@ -4,10 +4,8 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
-from git.test.lib import (
-    TestBase,
-    with_rw_repo
-)
+from itertools import chain
+
 from git import (
     Reference,
     Head,
@@ -18,11 +16,15 @@ from git import (
     GitCommandError,
     RefLog
 )
-import git.refs as refs
-from git.util import Actor
 from git.objects.tag import TagObject
-from itertools import chain
-import os
+from git.test.lib import (
+    TestBase,
+    with_rw_repo
+)
+from git.util import Actor
+
+import git.refs as refs
+import os.path as osp
 
 
 class TestRefs(TestBase):
@@ -268,10 +270,10 @@ class TestRefs(TestBase):
             assert tmp_head == new_head and tmp_head.object == new_head.object
 
             logfile = RefLog.path(tmp_head)
-            assert os.path.isfile(logfile)
+            assert osp.isfile(logfile)
             Head.delete(rw_repo, tmp_head)
             # deletion removes the log as well
-            assert not os.path.isfile(logfile)
+            assert not osp.isfile(logfile)
             heads = rw_repo.heads
             assert tmp_head not in heads and new_head not in heads
             # force on deletion testing would be missing here, code looks okay though ;)
@@ -450,12 +452,12 @@ class TestRefs(TestBase):
         symbol_ref_path = "refs/symbol_ref"
         symref = SymbolicReference(rw_repo, symbol_ref_path)
         assert symref.path == symbol_ref_path
-        symbol_ref_abspath = os.path.join(rw_repo.git_dir, symref.path)
+        symbol_ref_abspath = osp.join(rw_repo.git_dir, symref.path)
 
         # set it
         symref.reference = new_head
         assert symref.reference == new_head
-        assert os.path.isfile(symbol_ref_abspath)
+        assert osp.isfile(symbol_ref_abspath)
         assert symref.commit == new_head.commit
 
         for name in ('absname', 'folder/rela_name'):
@@ -507,7 +509,7 @@ class TestRefs(TestBase):
         rw_repo.head.reference = Head.create(rw_repo, "master")
 
         # At least the head should still exist
-        assert os.path.isfile(os.path.join(rw_repo.git_dir, 'HEAD'))
+        assert osp.isfile(osp.join(rw_repo.git_dir, 'HEAD'))
         refs = list(SymbolicReference.iter_items(rw_repo))
         assert len(refs) == 1
 
diff --git a/git/test/test_repo.py b/git/test/test_repo.py
index a0a6a5b0..8b644f7f 100644
--- a/git/test/test_repo.py
+++ b/git/test/test_repo.py
@@ -50,10 +50,9 @@ from git.test.lib import (
     assert_true,
     raises
 )
-from git.util import HIDE_WINDOWS_KNOWN_ERRORS
+from git.util import HIDE_WINDOWS_KNOWN_ERRORS, cygpath
 from git.test.lib import with_rw_directory
-from git.util import join_path_native, rmtree, rmfile
-from gitdb.util import bin_to_hex
+from git.util import join_path_native, rmtree, rmfile, bin_to_hex
 from unittest import SkipTest
 
 import functools as fnt
@@ -203,8 +202,8 @@ class TestRepo(TestBase):
         prev_cwd = os.getcwd()
         os.chdir(tempfile.gettempdir())
         git_dir_rela = "repos/foo/bar.git"
-        del_dir_abs = os.path.abspath("repos")
-        git_dir_abs = os.path.abspath(git_dir_rela)
+        del_dir_abs = osp.abspath("repos")
+        git_dir_abs = osp.abspath(git_dir_rela)
         try:
             # with specific path
             for path in (git_dir_rela, git_dir_abs):
@@ -212,7 +211,7 @@ class TestRepo(TestBase):
                 self.assertIsInstance(r, Repo)
                 assert r.bare is True
                 assert not r.has_separate_working_tree()
-                assert os.path.isdir(r.git_dir)
+                assert osp.isdir(r.git_dir)
 
                 self._assert_empty_repo(r)
 
@@ -306,16 +305,16 @@ class TestRepo(TestBase):
     def test_is_dirty_with_path(self, rwrepo):
         assert rwrepo.is_dirty(path="git") is False
 
-        with open(os.path.join(rwrepo.working_dir, "git", "util.py"), "at") as f:
+        with open(osp.join(rwrepo.working_dir, "git", "util.py"), "at") as f:
             f.write("junk")
         assert rwrepo.is_dirty(path="git") is True
         assert rwrepo.is_dirty(path="doc") is False
 
-        rwrepo.git.add(os.path.join("git", "util.py"))
+        rwrepo.git.add(Git.polish_url(osp.join("git", "util.py")))
         assert rwrepo.is_dirty(index=False, path="git") is False
         assert rwrepo.is_dirty(path="git") is True
 
-        with open(os.path.join(rwrepo.working_dir, "doc", "no-such-file.txt"), "wt") as f:
+        with open(osp.join(rwrepo.working_dir, "doc", "no-such-file.txt"), "wt") as f:
             f.write("junk")
         assert rwrepo.is_dirty(path="doc") is False
         assert rwrepo.is_dirty(untracked_files=True, path="doc") is True
@@ -412,6 +411,14 @@ class TestRepo(TestBase):
         self.assertEqual(len(res), 1)
         self.assertEqual(len(res[0][1]), 83, "Unexpected amount of parsed blame lines")
 
+    @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and Git.is_cygwin(),
+            """FIXME: File "C:\projects\gitpython\git\cmd.py", line 671, in execute
+                    raise GitCommandError(command, status, stderr_value, stdout_value)
+                GitCommandError: Cmd('git') failed due to: exit code(128)
+                  cmdline: git add 1__��ava verb��ten 1_test _myfile 1_test_other_file
+                          1_��ava-----verb��ten
+                  stderr: 'fatal: pathspec '"1__çava verböten"' did not match any files'
+                """)
     @with_rw_repo('HEAD', bare=False)
     def test_untracked_files(self, rwrepo):
         for run, (repo_add, is_invoking_git) in enumerate((
@@ -494,10 +501,10 @@ class TestRepo(TestBase):
         ph = os.environ.get('HOME')
         try:
             os.environ['HOME'] = rw_dir
-            Repo.init(os.path.join('~', 'test.git'), bare=True)
+            Repo.init(osp.join('~', 'test.git'), bare=True)
 
             os.environ['FOO'] = rw_dir
-            Repo.init(os.path.join('$FOO', 'test.git'), bare=True)
+            Repo.init(osp.join('$FOO', 'test.git'), bare=True)
         finally:
             if ph:
                 os.environ['HOME'] = ph
@@ -785,7 +792,7 @@ class TestRepo(TestBase):
     @with_rw_repo('HEAD')
     def test_git_file(self, rwrepo):
         # Move the .git directory to another location and create the .git file.
-        real_path_abs = os.path.abspath(join_path_native(rwrepo.working_tree_dir, '.real'))
+        real_path_abs = osp.abspath(join_path_native(rwrepo.working_tree_dir, '.real'))
         os.rename(rwrepo.git_dir, real_path_abs)
         git_file_path = join_path_native(rwrepo.working_tree_dir, '.git')
         with open(git_file_path, 'wb') as fp:
@@ -793,13 +800,13 @@ class TestRepo(TestBase):
 
         # Create a repo and make sure it's pointing to the relocated .git directory.
         git_file_repo = Repo(rwrepo.working_tree_dir)
-        self.assertEqual(os.path.abspath(git_file_repo.git_dir), real_path_abs)
+        self.assertEqual(osp.abspath(git_file_repo.git_dir), real_path_abs)
 
         # Test using an absolute gitdir path in the .git file.
         with open(git_file_path, 'wb') as fp:
             fp.write(('gitdir: %s\n' % real_path_abs).encode('ascii'))
         git_file_repo = Repo(rwrepo.working_tree_dir)
-        self.assertEqual(os.path.abspath(git_file_repo.git_dir), real_path_abs)
+        self.assertEqual(osp.abspath(git_file_repo.git_dir), real_path_abs)
 
     @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and PY3,
             "FIXME: smmp fails with: TypeError: Can't convert 'bytes' object to str implicitly")
@@ -840,7 +847,7 @@ class TestRepo(TestBase):
         # It's expected to not be able to access a tree
         self.failUnlessRaises(ValueError, r.tree)
 
-        new_file_path = os.path.join(rw_dir, "new_file.ext")
+        new_file_path = osp.join(rw_dir, "new_file.ext")
         touch(new_file_path)
         r.index.add([new_file_path])
         r.index.commit("initial commit\nBAD MESSAGE 1\n")
@@ -901,9 +908,6 @@ class TestRepo(TestBase):
         for i, j in itertools.permutations([c1, 'ffffff', ''], r=2):
             self.assertRaises(GitCommandError, repo.is_ancestor, i, j)
 
-    # @skipIf(HIDE_WINDOWS_KNOWN_ERRORS,
-    #         "FIXME: helper.wrapper fails with: PermissionError: [WinError 5] Access is denied: "
-    #         "'C:\\Users\\appveyor\\AppData\\Local\\Temp\\1\\test_work_tree_unsupportedryfa60di\\master_repo\\.git\\objects\\pack\\pack-bc9e0787aef9f69e1591ef38ea0a6f566ec66fe3.idx")  # noqa E501
     @with_rw_directory
     def test_work_tree_unsupported(self, rw_dir):
         git = Git(rw_dir)
@@ -913,6 +917,8 @@ class TestRepo(TestBase):
         rw_master = self.rorepo.clone(join_path_native(rw_dir, 'master_repo'))
         rw_master.git.checkout('HEAD~10')
         worktree_path = join_path_native(rw_dir, 'worktree_repo')
+        if Git.is_cygwin():
+            worktree_path = cygpath(worktree_path)
         try:
             rw_master.git.worktree('add', worktree_path, 'master')
         except Exception as ex:
diff --git a/git/test/test_submodule.py b/git/test/test_submodule.py
index 9db4f9c9..fcaad04b 100644
--- a/git/test/test_submodule.py
+++ b/git/test/test_submodule.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 import os
@@ -6,24 +7,34 @@ from unittest.case import skipIf
 
 import git
 from git.cmd import Git
-from git.compat import string_types, is_win
+from git.compat import (
+    string_types,
+    is_win,
+)
 from git.exc import (
     InvalidGitRepositoryError,
     RepositoryDirtyError
 )
 from git.objects.submodule.base import Submodule
-from git.objects.submodule.root import RootModule, RootUpdateProgress
+from git.objects.submodule.root import (
+    RootModule,
+    RootUpdateProgress,
+)
 from git.repo.fun import (
     find_git_dir,
-    touch
+    touch,
 )
 from git.test.lib import (
     TestBase,
-    with_rw_repo
+    with_rw_repo,
 )
 from git.test.lib import with_rw_directory
-from git.util import HIDE_WINDOWS_KNOWN_ERRORS
-from git.util import to_native_path_linux, join_path_native
+from git.util import (
+    to_native_path_linux,
+    join_path_native,
+    HIDE_WINDOWS_KNOWN_ERRORS,
+)
+
 import os.path as osp
 
 
@@ -673,6 +684,13 @@ class TestSubmodule(TestBase):
                                   url=empty_repo_dir, no_checkout=checkout_mode and True or False)
         # end for each checkout mode
 
+    @skipIf(HIDE_WINDOWS_KNOWN_ERRORS and Git.is_cygwin(),
+            """FIXME: ile "C:\projects\gitpython\git\cmd.py", line 671, in execute
+                raise GitCommandError(command, status, stderr_value, stdout_value)
+            GitCommandError: Cmd('git') failed due to: exit code(128)
+              cmdline: git add 1__Xava verbXXten 1_test _myfile 1_test_other_file 1_XXava-----verbXXten
+              stderr: 'fatal: pathspec '"1__çava verböten"' did not match any files'
+                """)
     @with_rw_directory
     def test_git_submodules_and_add_sm_with_new_commit(self, rwdir):
         parent = git.Repo.init(osp.join(rwdir, 'parent'))
@@ -705,7 +723,7 @@ class TestSubmodule(TestBase):
         fp = osp.join(smm.working_tree_dir, 'empty-file')
         with open(fp, 'w'):
             pass
-        smm.git.add(fp)
+        smm.git.add(Git.polish_url(fp))
         smm.git.commit(m="new file added")
 
         # submodules are retrieved from the current commit's tree, therefore we can't really get a new submodule
@@ -730,7 +748,7 @@ class TestSubmodule(TestBase):
         assert commit_sm.binsha == sm_too.binsha
         assert sm_too.binsha != sm.binsha
 
-    # @skipIf(HIDE_WINDOWS_KNOWN_ERRORS,
+    # @skipIf(HIDE_WINDOWS_KNOWN_ERRORS,  ## ACTUALLY skipped by `git.submodule.base#L869`.
     #         "FIXME: helper.wrapper fails with: PermissionError: [WinError 5] Access is denied: "
     #         "'C:\\Users\\appveyor\\AppData\\Local\\Temp\\1\\test_work_tree_unsupportedryfa60di\\master_repo\\.git\\objects\\pack\\pack-bc9e0787aef9f69e1591ef38ea0a6f566ec66fe3.idx")  # noqa E501
     @with_rw_directory
diff --git a/git/test/test_tree.py b/git/test/test_tree.py
index f36c4337..f9259874 100644
--- a/git/test/test_tree.py
+++ b/git/test/test_tree.py
@@ -5,7 +5,6 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 from io import BytesIO
-import os
 import sys
 from unittest.case import skipIf
 
@@ -13,8 +12,10 @@ from git import (
     Tree,
     Blob
 )
-from git.util import HIDE_WINDOWS_KNOWN_ERRORS
 from git.test.lib import TestBase
+from git.util import HIDE_WINDOWS_KNOWN_ERRORS
+
+import os.path as osp
 
 
 class TestTree(TestBase):
@@ -90,12 +91,12 @@ class TestTree(TestBase):
         assert len(set(b for b in root if isinstance(b, Blob)) | set(root.blobs)) == len(root.blobs)
         subitem = trees[0][0]
         assert "/" in subitem.path
-        assert subitem.name == os.path.basename(subitem.path)
+        assert subitem.name == osp.basename(subitem.path)
 
         # assure that at some point the traversed paths have a slash in them
         found_slash = False
         for item in root.traverse():
-            assert os.path.isabs(item.abspath)
+            assert osp.isabs(item.abspath)
             if '/' in item.path:
                 found_slash = True
             # END check for slash
diff --git a/git/test/test_util.py b/git/test/test_util.py
index e07417b4..8f8d2272 100644
--- a/git/test/test_util.py
+++ b/git/test/test_util.py
@@ -5,7 +5,19 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 import tempfile
+import time
+from unittest.case import skipIf
+
+import ddt
 
+from git.cmd import dashify
+from git.compat import string_types, is_win
+from git.objects.util import (
+    altz_to_utctz_str,
+    utctz_to_altz,
+    verify_utctz,
+    parse_date,
+)
 from git.test.lib import (
     TestBase,
     assert_equal
@@ -15,19 +27,37 @@ from git.util import (
     BlockingLockFile,
     get_user_id,
     Actor,
-    IterableList
+    IterableList,
+    cygpath,
+    decygpath
 )
-from git.objects.util import (
-    altz_to_utctz_str,
-    utctz_to_altz,
-    verify_utctz,
-    parse_date,
+
+
+_norm_cygpath_pairs = (
+    (r'foo\bar', 'foo/bar'),
+    (r'foo/bar', 'foo/bar'),
+
+    (r'C:\Users', '/cygdrive/c/Users'),
+    (r'C:\d/e', '/cygdrive/c/d/e'),
+
+    ('C:\\', '/cygdrive/c/'),
+
+    (r'\\server\C$\Users', '//server/C$/Users'),
+    (r'\\server\C$', '//server/C$'),
+    ('\\\\server\\c$\\', '//server/c$/'),
+    (r'\\server\BAR/', '//server/BAR/'),
+
+    (r'D:/Apps', '/cygdrive/d/Apps'),
+    (r'D:/Apps\fOO', '/cygdrive/d/Apps/fOO'),
+    (r'D:\Apps/123', '/cygdrive/d/Apps/123'),
 )
-from git.cmd import dashify
-from git.compat import string_types, is_win
 
-import time
-import ddt
+_unc_cygpath_pairs = (
+    (r'\\?\a:\com', '/cygdrive/a/com'),
+    (r'\\?\a:/com', '/cygdrive/a/com'),
+
+    (r'\\?\UNC\server\D$\Apps', '//server/D$/Apps'),
+)
 
 
 class TestIterableMember(object):
@@ -52,6 +82,46 @@ class TestUtils(TestBase):
             "array": [42],
         }
 
+    @skipIf(not is_win, "Paths specifically for Windows.")
+    @ddt.idata(_norm_cygpath_pairs + _unc_cygpath_pairs)
+    def test_cygpath_ok(self, case):
+        wpath, cpath = case
+        cwpath = cygpath(wpath)
+        self.assertEqual(cwpath, cpath, wpath)
+
+    @skipIf(not is_win, "Paths specifically for Windows.")
+    @ddt.data(
+        (r'./bar', 'bar'),
+        (r'.\bar', 'bar'),
+        (r'../bar', '../bar'),
+        (r'..\bar', '../bar'),
+        (r'../bar/.\foo/../chu', '../bar/chu'),
+    )
+    def test_cygpath_norm_ok(self, case):
+        wpath, cpath = case
+        cwpath = cygpath(wpath)
+        self.assertEqual(cwpath, cpath or wpath, wpath)
+
+    @skipIf(not is_win, "Paths specifically for Windows.")
+    @ddt.data(
+        r'C:',
+        r'C:Relative',
+        r'D:Apps\123',
+        r'D:Apps/123',
+        r'\\?\a:rel',
+        r'\\share\a:rel',
+    )
+    def test_cygpath_invalids(self, wpath):
+        cwpath = cygpath(wpath)
+        self.assertEqual(cwpath, wpath.replace('\\', '/'), wpath)
+
+    @skipIf(not is_win, "Paths specifically for Windows.")
+    @ddt.idata(_norm_cygpath_pairs)
+    def test_decygpath(self, case):
+        wpath, cpath = case
+        wcpath = decygpath(cpath)
+        self.assertEqual(wcpath, wpath.replace('/', '\\'), cpath)
+
     def test_it_should_dashify(self):
         assert_equal('this-is-my-argument', dashify('this_is_my_argument'))
         assert_equal('foo', dashify('foo'))