commit: when creating a new commit and advancing the head, it will now write the ORIG_HEAD reference as well

Author: Byron

lib/git/objects/commit.py

@@ -365,7 +365,13 @@ def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False):
 		new_commit.binsha = istream.binsha
 
 		if head:
+			# need late import here, importing git at the very beginning throws
+			# as well ... 
+			import git.refs
 			try:
+				cur_commit = repo.head.commit
+				# Adjust the original head reference - force it
+				git.refs.SymbolicReference.create(repo, 'ORIG_HEAD', cur_commit, force=True)
 				repo.head.commit = new_commit
 			except ValueError:
 				# head is not yet set to the ref our HEAD points to

lib/git/refs.py

@@ -277,7 +277,7 @@ def is_detached(self):
 	@classmethod
 	def to_full_path(cls, path):
 		"""
-		:return: string with a full path name which can be used to initialize 
+		:return: string with a full repository-relative path which can be used to initialize 
 			a Reference instance, for instance by using ``Reference.from_path``"""
 		if isinstance(path, SymbolicReference):
 			path = path.path

test/git/test_index.py

@@ -409,6 +409,7 @@ def mixed_iterator():
 		commit_message = "commit default head"
 
 		new_commit = index.commit(commit_message, head=False)
+		assert cur_commit != new_commit
 		assert new_commit.author.name == uname
 		assert new_commit.author.email == umail
 		assert new_commit.committer.name == uname
@@ -421,6 +422,7 @@ def mixed_iterator():
 		# same index, no parents
 		commit_message = "index without parents"
 		commit_no_parents = index.commit(commit_message, parent_commits=list(), head=True)
+		assert SymbolicReference(rw_repo, 'ORIG_HEAD').commit == cur_commit
 		assert commit_no_parents.message == commit_message
 		assert len(commit_no_parents.parents) == 0
 		assert cur_head.commit == commit_no_parents