# HG changeset patch
# User Boris Feld <boris.feld@octobus.net>
# Date 2017-05-04 00:23:21
# Node ID 8810f0643fa1cd363f5a1c4e84ed80e3a7a5ae7f
# Parent  2b9e2415f5b5d440734ccdf2fc79561c7c104635

changelog: introduce a 'tiprev' method

Accessing tiprev is a common need through the code base. It is usually done
using "len(changelog) -1". That form is tedious and error-prone. For example,
it will give wrong results on filtered changelog (if the unfiltered tip is
filtered).

As a result, we introduce a simple 'tiprev()' method to provide this exact
information in a nice way.

diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -295,6 +295,11 @@ class changelog(revlog.revlog):
         self._divert = False
         self.filteredrevs = frozenset()
 
+    def tiprev(self):
+        for i in xrange(len(self) -1, -2, -1):
+            if i not in self.filteredrevs:
+                return i
+
     def tip(self):
         """filtered version of revlog.tip"""
         for i in xrange(len(self) -1, -2, -1):