WIP: use cygpath.exe to convert Windows paths and respect mount-points

doc/source/changes.rst

@@ -6,6 +6,10 @@ Changelog
 ====================================
 
 * support for worktrees
+* fix(cygwin): use ``cygpath.exe`` to convert *Windows* paths and respect
+  different mount-points (e.g. *MSYS2* which is a *Cygwin* clone mounts drives
+  under root).
+
 
 2.1.3 - Bugfixes
 ====================================
@@ -34,7 +38,7 @@ Notable fixes
 * The `GIT_DIR` environment variable does not override the `path` argument when
   initializing a `Repo` object anymore. However, if said `path` unset, `GIT_DIR`
   will be used to fill the void.
-  
+
 All issues and PRs can be viewed in all detail when following this URL:
 https://github.com/gitpython-developers/GitPython/issues?q=is%3Aclosed+milestone%3A%22v2.1.0+-+proper+windows+support%22
 
@@ -63,7 +67,7 @@ https://github.com/gitpython-developers/GitPython/issues?q=is%3Aclosed+milestone
 2.0.7 - New Features
 ====================
 
-* `IndexFile.commit(...,skip_hooks=False)` added. This parameter emulates the 
+* `IndexFile.commit(...,skip_hooks=False)` added. This parameter emulates the
    behaviour of `--no-verify` on the command-line.
 
 2.0.6 - Fixes and Features
@@ -103,7 +107,7 @@ https://github.com/gitpython-developers/GitPython/issues?q=is%3Aclosed+milestone
   commit messages contained ``\r`` characters
 * Fix: progress handler exceptions are not caught anymore, which would usually just hide bugs
   previously.
-* Fix: The `Git.execute` method will now redirect `stdout` to `devnull` if `with_stdout` is false, 
+* Fix: The `Git.execute` method will now redirect `stdout` to `devnull` if `with_stdout` is false,
   which is the intended behaviour based on the parameter's documentation.
 
 2.0.2 - Fixes

git/util.py

@@ -18,6 +18,10 @@
     from unittest import SkipTest
 except ImportError:
     from unittest2 import SkipTest
+try:
+    from functools import lru_cache
+except ImportError:
+    from repoze.lru import lru_cache
 
 from gitdb.util import (# NOQA @IgnorePep8
     make_sha,
@@ -221,7 +225,28 @@ def is_exec(fpath):
     return progs
 
 
-def _cygexpath(drive, path):
+def _cygpath(winpath, inverse=False):
+    """Invokes `cygpath` cmd to parse Windoews paths."""
+    import subprocess as sbp
+
+    cmd = ['cygpath', winpath]
+    if inverse:
+        cmd.insert(1, '-w')
+    try:
+        cygpath = sbp.check_output(cmd, universal_newlines=True)
+        if cygpath and cygpath[-1] == '\n':
+            cygpath = cygpath[:-1]
+    except Exception as ex:
+        log.warning("`cygpath.exe` failed on '%s' due to: %s"
+                    "  Using winpath as it is.",
+                    winpath, ex)
+    else:
+        winpath = cygpath
+
+    return winpath
+
+
+def _cyg_regex_path(drive, path):
     if osp.isabs(path) and not drive:
         ## Invoked from `cygpath()` directly with `D:Apps\123`?
         #  It's an error, leave it alone just slashes)
@@ -235,7 +260,7 @@ def _cygexpath(drive, path):
             else:
                 p = cygpath(p)
         elif drive:
-            p = '/cygdrive/%s/%s' % (drive.lower(), p)
+            return _cygpath('%s:\\%s' % (drive, p))
 
     return p.replace('\\', '/')
 
@@ -249,12 +274,12 @@ def _cygexpath(drive, path):
      ),
 
     (re.compile(r"\\\\\?\\(\w):[/\\](.*)"),
-     _cygexpath,
+     _cyg_regex_path,
      False
      ),
 
     (re.compile(r"(\w):[/\\](.*)"),
-     _cygexpath,
+     _cyg_regex_path,
      False
      ),
 
@@ -268,39 +293,42 @@ def _cygexpath(drive, path):
 )
 
 
+@lru_cache(500)  # Size arg required only for py3.2 backport `repoze.lru` lib.
 def cygpath(path):
     """Use :meth:`git.cmd.Git.polish_url()` instead, that works on any environment."""
-    if not path.startswith(('/cygdrive', '//')):
-        for regex, parser, recurse in _cygpath_parsers:
-            match = regex.match(path)
-            if match:
-                path = parser(*match.groups())
-                if recurse:
-                    path = cygpath(path)
-                break
-        else:
-            path = _cygexpath(None, path)
+    for regex, parser, recurse in _cygpath_parsers:
+        match = regex.match(path)
+        if match:
+            path = parser(*match.groups())
+            if recurse:
+                path = cygpath(path)
+            break
+    else:
+        path = _cyg_regex_path(None, path)
 
     return path
 
 
 _decygpath_regex = re.compile(r"/cygdrive/(\w)(/.*)?")
 
 
+@lru_cache(500)  # Size arg required only for py3.2 backport `repoze.lru` lib.
 def decygpath(path):
-    m = _decygpath_regex.match(path)
-    if m:
-        drive, rest_path = m.groups()
-        path = '%s:%s' % (drive.upper(), rest_path or '')
+    if path:
+        winpath = _cygpath(path, inverse=True)
+        if path[-1] in '/\\' and winpath[-1] not in '/\\':
+            winpath += '\\'
+        path = winpath
 
-    return path.replace('/', '\\')
+    return path
 
 
 #: Store boolean flags denoting if a specific Git executable
 #: is from a Cygwin installation (since `cache_lru()` unsupported on PY2).
 _is_cygwin_cache = {}
 
 
+@lru_cache(50)  # Size arg required only for py3.2 backport `repoze.lru` lib.
 def is_cygwin_git(git_executable):
     if not is_win:
         return False
@@ -322,7 +350,7 @@ def is_cygwin_git(git_executable):
                                        universal_newlines=True)
             uname_out, _ = process.communicate()
             #retcode = process.poll()
-            is_cygwin = 'CYGWIN' in uname_out
+            is_cygwin = 'CYGWIN' in uname_out or 'MSYS' in uname_out
         except Exception as ex:
             log.debug('Failed checking if running in CYGWIN due to: %r', ex)
         _is_cygwin_cache[git_executable] = is_cygwin

requirements.txt

@@ -1,3 +1,5 @@
 gitdb>=0.6.4
 ddt>=1.1.1
+ordereddict; python_version < '2.7'
+repoze.lru; python_version < '3.2'
 unittest2; python_version < '2.7'

setup.py

@@ -68,6 +68,7 @@ def _stamp_version(filename):
 install_requires = ['gitdb2 >= 2.0.0']
 extras_require = {
     ':python_version == "2.6"': ['ordereddict'],
+    ':python_version < "3.2"': ['repoze.lru'],
 }
 test_requires = ['ddt>=1.1.1']
 if sys.version_info[:2] < (2, 7):