@@ -190,7 +190,12 @@ def rev_parse(repo, rev):
 					raise NotImplementedError("Support for additional @{...} modes not implemented")
 				#END handle revlog index
 
-				entry = ref.log()[revlog_index]
+				try:
+					entry = ref.log()[revlog_index]
+				except IndexError:
+					raise BadObject("Invalid revlog index: %i" % revlog_index)
+				#END handle index out of bound
+				
 				obj = Object.new_from_sha(repo, hex_to_bin(entry.newhexsha))
 
 				# make it pass the following checks
 
@@ -557,12 +557,19 @@ def test_rev_parse(self):
 		# uses HEAD.ref by default
 		assert rev_parse('@{0}') == head.commit
 		if not head.is_detached:
-			assert rev_parse('%s@{0}' % head.ref.name) == head.ref.commit
+			refspec = '%s@{0}' % head.ref.name
+			assert rev_parse(refspec) == head.ref.commit
+			# all additional specs work as well
+			assert rev_parse(refspec+"^{tree}") == head.commit.tree
+			assert rev_parse(refspec+":CHANGES").type == 'blob'
 		#END operate on non-detached head
 
 		# the last position
 		assert rev_parse('@{1}') != head.commit
 
+		# position doesn't exist
+		self.failUnlessRaises(BadObject, rev_parse, '@{10000}')
+		
 		# currently, nothing more is supported
 		self.failUnlessRaises(NotImplementedError, rev_parse, "@{1 week ago}")