refs.SymoblicRef: implemented direcft setting of the symbolic references commit, which possibly dereferences to the respective head

Author: Byron

lib/git/refs.py

@@ -118,7 +118,7 @@ def _get_commit(self):
 		"""
 		commit = self.object
 		if commit.type != "commit":
-			raise TypeError("Object of reference %s did not point to a commit" % self)
+			raise TypeError("Object of reference %s did not point to a commit, but to %r" % (self, commit))
 		return commit
 
 	commit = property(_get_commit, _set_commit, doc="Return Commit object the reference points to")
@@ -250,8 +250,7 @@ def __hash__(self):
 	def _get_path(self):
 		return os.path.join(self.repo.path, self.name)
 
-	@property
-	def commit(self):
+	def _get_commit(self):
 		"""
 		Returns:
 			Commit object we point to, works for detached and non-detached 
@@ -271,6 +270,18 @@ def commit(self):
 		# Otherwise it would have detached it
 		return Head(self.repo, tokens[1]).commit
 
+	def _set_commit(self, commit):
+		"""
+		Set our commit, possibly dereference our symbolic reference first.
+		"""
+		if self.is_detached:
+			return self._set_reference(commit)
+			
+		# set the commit on our reference
+		self._get_reference().commit = commit
+	
+	commit = property(_get_commit, _set_commit, doc="Query or set commits directly")
+		
 	def _get_reference(self):
 		"""
 		Returns

test/git/test_refs.py

@@ -198,3 +198,21 @@ def test_head_reset(self, rw_repo):
 		assert head.commit == old_commit		# and the ref did not change
 		head.object = head_tree
 		assert head.object == head_tree
+		self.failUnlessRaises(TypeError, getattr, head, 'commit')	# object is a tree, not a commit
+		
+		# set the commit directly using the head. This would never detach the head
+		assert not cur_head.is_detached
+		head.object = old_commit
+		cur_head.reference = head.commit
+		assert cur_head.is_detached
+		parent_commit = head.commit.parents[0]
+		assert cur_head.is_detached
+		cur_head.commit = parent_commit
+		assert cur_head.is_detached and cur_head.commit == parent_commit
+		
+		cur_head.reference = head
+		assert not cur_head.is_detached
+		cur_head.commit = parent_commit
+		assert not cur_head.is_detached
+		assert head.commit == parent_commit
+