1 files changed, 246 insertions, 0 deletions
diff --git a/git/refs/head.py b/git/refs/head.py
new file mode 100644
index 00000000..d8729434
--- /dev/null
+++ b/git/refs/head.py
@@ -0,0 +1,246 @@
+from symbolic import SymbolicReference
+from reference import Reference
+
+from git.config import SectionConstraint
+
+from git.util import join_path
+
+from git.exc import GitCommandError
+
+__all__ = ["HEAD", "Head"]
+
+
+	
+class HEAD(SymbolicReference):
+	"""Special case of a Symbolic Reference as it represents the repository's 
+	HEAD reference."""
+	_HEAD_NAME = 'HEAD'
+	_ORIG_HEAD_NAME = 'ORIG_HEAD'
+	__slots__ = tuple()
+	
+	def __init__(self, repo, path=_HEAD_NAME):
+		if path != self._HEAD_NAME:
+			raise ValueError("HEAD instance must point to %r, got %r" % (self._HEAD_NAME, path))
+		super(HEAD, self).__init__(repo, path)
+	
+	def orig_head(self):
+		"""
+		:return: SymbolicReference pointing at the ORIG_HEAD, which is maintained 
+			to contain the previous value of HEAD"""
+		return SymbolicReference(self.repo, self._ORIG_HEAD_NAME)
+		
+	def reset(self, commit='HEAD', index=True, working_tree = False, 
+				paths=None, **kwargs):
+		"""Reset our HEAD to the given commit optionally synchronizing 
+		the index and working tree. The reference we refer to will be set to 
+		commit as well.
+		
+		:param commit:
+			Commit object, Reference Object or string identifying a revision we 
+			should reset HEAD to.
+			
+		:param index:
+			If True, the index will be set to match the given commit. Otherwise
+			it will not be touched.
+		
+		:param working_tree:
+			If True, the working tree will be forcefully adjusted to match the given
+			commit, possibly overwriting uncommitted changes without warning.
+			If working_tree is True, index must be true as well
+		
+		:param paths:
+			Single path or list of paths relative to the git root directory
+			that are to be reset. This allows to partially reset individual files.
+		
+		:param kwargs:
+			Additional arguments passed to git-reset. 
+		
+		:return: self"""
+		mode = "--soft"
+		add_arg = None
+		if index:
+			mode = "--mixed"
+			
+			# it appears, some git-versions declare mixed and paths deprecated
+			# see http://github.com/Byron/GitPython/issues#issue/2
+			if paths:
+				mode = None
+			# END special case
+		# END handle index
+			
+		if working_tree:
+			mode = "--hard"
+			if not index:
+				raise ValueError( "Cannot reset the working tree if the index is not reset as well")
+			
+		# END working tree handling
+		
+		if paths:
+			add_arg = "--"
+		# END nicely separate paths from rest
+		
+		try:
+			self.repo.git.reset(mode, commit, add_arg, paths, **kwargs)
+		except GitCommandError, e:
+			# git nowadays may use 1 as status to indicate there are still unstaged
+			# modifications after the reset
+			if e.status != 1:
+				raise
+		# END handle exception
+		
+		return self
+	
+
+class Head(Reference):
+	"""A Head is a named reference to a Commit. Every Head instance contains a name
+	and a Commit object.
+
+	Examples::
+
+		>>> repo = Repo("/path/to/repo")
+		>>> head = repo.heads[0]
+
+		>>> head.name
+		'master'
+
+		>>> head.commit
+		<git.Commit "1c09f116cbc2cb4100fb6935bb162daa4723f455">
+
+		>>> head.commit.hexsha
+		'1c09f116cbc2cb4100fb6935bb162daa4723f455'"""
+	_common_path_default = "refs/heads"
+	k_config_remote = "remote"
+	k_config_remote_ref = "merge"			# branch to merge from remote
+	
+	@classmethod
+	def delete(cls, repo, *heads, **kwargs):
+		"""Delete the given heads
+		:param force:
+			If True, the heads will be deleted even if they are not yet merged into
+			the main development stream.
+			Default False"""
+		force = kwargs.get("force", False)
+		flag = "-d"
+		if force:
+			flag = "-D"
+		repo.git.branch(flag, *heads)
+		
+	def set_tracking_branch(self, remote_reference):
+		"""
+		Configure this branch to track the given remote reference. This will alter
+			this branch's configuration accordingly.
+		
+		:param remote_reference: The remote reference to track or None to untrack 
+			any references
+		:return: self"""
+		if remote_reference is not None and not isinstance(remote_reference, RemoteReference):
+			raise ValueError("Incorrect parameter type: %r" % remote_reference)
+		# END handle type
+		
+		writer = self.config_writer()
+		if remote_reference is None:
+			writer.remove_option(self.k_config_remote)
+			writer.remove_option(self.k_config_remote_ref)
+			if len(writer.options()) == 0:
+				writer.remove_section()
+			# END handle remove section
+		else:
+			writer.set_value(self.k_config_remote, remote_reference.remote_name)
+			writer.set_value(self.k_config_remote_ref, Head.to_full_path(remote_reference.remote_head))
+		# END handle ref value
+		
+		return self
+		
+		
+	def tracking_branch(self):
+		"""
+		:return: The remote_reference we are tracking, or None if we are 
+			not a tracking branch"""
+		reader = self.config_reader()
+		if reader.has_option(self.k_config_remote) and reader.has_option(self.k_config_remote_ref):
+			ref = Head(self.repo, Head.to_full_path(reader.get_value(self.k_config_remote_ref)))
+			remote_refpath = RemoteReference.to_full_path(join_path(reader.get_value(self.k_config_remote), ref.name))
+			return RemoteReference(self.repo, remote_refpath)
+		# END handle have tracking branch
+		
+		# we are not a tracking branch
+		return None
+	
+	def rename(self, new_path, force=False):
+		"""Rename self to a new path
+		
+		:param new_path:
+			Either a simple name or a path, i.e. new_name or features/new_name.
+			The prefix refs/heads is implied
+			
+		:param force:
+			If True, the rename will succeed even if a head with the target name
+			already exists.
+			
+		:return: self
+		:note: respects the ref log as git commands are used"""
+		flag = "-m"
+		if force:
+			flag = "-M"
+			
+		self.repo.git.branch(flag, self, new_path)
+		self.path  = "%s/%s" % (self._common_path_default, new_path)
+		return self
+		
+	def checkout(self, force=False, **kwargs):
+		"""Checkout this head by setting the HEAD to this reference, by updating the index
+		to reflect the tree we point to and by updating the working tree to reflect 
+		the latest index.
+		
+		The command will fail if changed working tree files would be overwritten.
+		
+		:param force:
+			If True, changes to the index and the working tree will be discarded.
+			If False, GitCommandError will be raised in that situation.
+			
+		:param kwargs:
+			Additional keyword arguments to be passed to git checkout, i.e.
+			b='new_branch' to create a new branch at the given spot.
+		
+		:return:
+			The active branch after the checkout operation, usually self unless
+			a new branch has been created.
+		
+		:note:
+			By default it is only allowed to checkout heads - everything else
+			will leave the HEAD detached which is allowed and possible, but remains
+			a special state that some tools might not be able to handle."""
+		args = list()
+		kwargs['f'] = force
+		if kwargs['f'] == False:
+			kwargs.pop('f')
+		
+		self.repo.git.checkout(self, **kwargs)
+		return self.repo.active_branch
+		
+	#{ Configruation
+	
+	def _config_parser(self, read_only):
+		if read_only:
+			parser = self.repo.config_reader()
+		else:
+			parser = self.repo.config_writer()
+		# END handle parser instance
+		
+		return SectionConstraint(parser, 'branch "%s"' % self.name)
+	
+	def config_reader(self):
+		"""
+		:return: A configuration parser instance constrained to only read 
+			this instance's values"""
+		return self._config_parser(read_only=True)
+		
+	def config_writer(self):
+		"""
+		:return: A configuration writer instance with read-and write acccess
+			to options of this head"""
+		return self._config_parser(read_only=False)
+	
+	#} END configuration
+		
+