Added search_parent_directories keyword argument to Repo type.

Now by default, we will not walk up the directory structure and possibly find
git directories that the user didn't intend to find.
If required, that kind of behaviour can be turned back on.

Fixes gitpython-developers#65

Author: Byron

doc/source/changes.rst

@@ -8,6 +8,7 @@ Changelog
 * diff() can now properly detect renames, both in patch and raw format. Previously it only worked when create_patch was True.
 * repo.odb.update_cache() is now called automatically after fetch and pull operations. In case you did that in your own code, you might want to remove your line to prevent a double-update that causes unnecessary IO.
 * A list of all fixed issues can be found here: https://github.com/gitpython-developers/GitPython/issues?q=milestone%3A%22v0.3.5+-+bugfixes%22+
+* `Repo(path)` will not automatically search upstream anymore and find any git directory on its way up. If you need that behaviour, you can turn it back on using the new `search_parent_directories=True` flag when constructing a `Repo` object.
 
 0.3.4 - Python 3 Support
 ========================

git/repo/base.py

@@ -46,7 +46,6 @@
     rev_parse,
     is_git_dir,
     find_git_dir,
-    read_gitfile,
     touch,
 )
 from git.compat import (
@@ -96,7 +95,7 @@ class Repo(object):
     # represents the configuration level of a configuration file
     config_level = ("system", "global", "repository")
 
-    def __init__(self, path=None, odbt=DefaultDBType):
+    def __init__(self, path=None, odbt=DefaultDBType, search_parent_directories=False):
         """Create a new Repo instance
 
         :param path: is the path to either the root git directory or the bare git repo::
@@ -128,15 +127,14 @@ def __init__(self, path=None, odbt=DefaultDBType):
                 self.git_dir = curpath
                 self._working_tree_dir = os.path.dirname(curpath)
                 break
+
             gitpath = find_git_dir(join(curpath, '.git'))
             if gitpath is not None:
                 self.git_dir = gitpath
                 self._working_tree_dir = curpath
                 break
-            gitpath = read_gitfile(curpath)
-            if gitpath:
-                self.git_dir = gitpath
-                self._working_tree_dir = curpath
+            
+            if not search_parent_directories:
                 break
             curpath, dummy = os.path.split(curpath)
             if not dummy:

git/repo/fun.py

@@ -19,8 +19,8 @@
 from git.compat import xrange
 
 
-__all__ = ('rev_parse', 'is_git_dir', 'touch', 'read_gitfile', 'find_git_dir', 'name_to_object',
-           'short_to_long', 'deref_tag', 'to_commit')
+__all__ = ('rev_parse', 'is_git_dir', 'touch', 'find_git_dir', 'name_to_object', 'short_to_long', 'deref_tag', 
+           'to_commit')
 
 
 def touch(filename):
@@ -44,32 +44,21 @@ def is_git_dir(d):
 def find_git_dir(d):
     if is_git_dir(d):
         return d
-    elif isfile(d):
+
+    try:
         with open(d) as fp:
             content = fp.read().rstrip()
+    except (IOError, OSError):
+        # it's probably not a file
+        pass
+    else:
         if content.startswith('gitdir: '):
             d = join(dirname(d), content[8:])
             return find_git_dir(d)
+    # end handle exception
     return None
 
 
-def read_gitfile(f):
-    """ This is taken from the git setup.c:read_gitfile function.
-    :return gitdir path or None if gitfile is invalid."""
-    if f is None:
-        return None
-    try:
-        line = open(f, 'r').readline().rstrip()
-    except (OSError, IOError):
-        # File might not exist or is unreadable - ignore
-        return None
-    # end handle file access
-    if line[0:8] != 'gitdir: ':
-        return None
-    path = os.path.realpath(line[8:])
-    return path if is_git_dir(path) else None
-
-
 def short_to_long(odb, hexsha):
     """:return: long hexadecimal sha1 from the given less-than-40 byte hexsha
         or None if no candidate could be found.

git/test/performance/lib.py

@@ -56,8 +56,8 @@ def setUp(self):
                 "your choice - defaulting to the gitpython repository")
             repo_path = os.path.dirname(__file__)
         # end set some repo path
-        self.gitrorepo = Repo(repo_path, odbt=GitCmdObjectDB)
-        self.puregitrorepo = Repo(repo_path, odbt=GitDB)
+        self.gitrorepo = Repo(repo_path, odbt=GitCmdObjectDB, search_parent_directories=True)
+        self.puregitrorepo = Repo(repo_path, odbt=GitDB, search_parent_directories=True)
 
     def tearDown(self):
         self.gitrorepo.git.clear_cache()