def _calc_changelog(self,ebuildpath,current,next):

		if ebuildpath == None or not os.path.exists(ebuildpath):

			return []

		current = '-'.join(portage.catpkgsplit(current)[1:])

		if current.endswith('-r0'):

			current = current[:-3]

		next = '-'.join(portage.catpkgsplit(next)[1:])

		if next.endswith('-r0'):

			next = next[:-3]

		changelogpath = os.path.join(os.path.split(ebuildpath)[0],'ChangeLog')

		try:

			changelog = open(changelogpath).read()

		except SystemExit, e:

			raise # Needed else can't exit

		except:

			return []

		divisions = self.find_changelog_tags(changelog)

		#print 'XX from',current,'to',next

		#for div,text in divisions: print 'XX',div

		# skip entries for all revisions above the one we are about to emerge

		for i in range(len(divisions)):

			if divisions[i][0]==next:

				divisions = divisions[i:]

				break

		# find out how many entries we are going to display

		for i in range(len(divisions)):

			if divisions[i][0]==current:

				divisions = divisions[:i]

				break

		else:

		    # couldnt find the current revision in the list. display nothing

			return []

		return divisions

	def _find_changelog_tags(self,changelog):

		divs = []

		release = None

		while 1:

			match = re.search(r'^\*\ ?([-a-zA-Z0-9_.+]*)(?:\ .*)?\n',changelog,re.M)

			if match is None:

				if release is not None:

					divs.append((release,changelog))

				return divs

			if release is not None:

				divs.append((release,changelog[:match.start()]))

			changelog = changelog[match.end():]

			release = match.group(1)

			if release.endswith('.ebuild'):

				release = release[:-7]

			if release.endswith('-r0'):

				release = release[:-3]