D4016: revlog: remove some knowledge of sentinel nullid in index

[martinvonz (Martin von Zweigbergk)]

martinvonz created this revision.
Herald added a reviewer: indygreg.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  I think the "-2" to mean "last position in index, not counting the
  null revision at the end" is an implementation detail of the index
  that we should avoid spreading knowledge of. I hope we can even remove
  support for index[-2].

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4016

AFFECTED FILES
  mercurial/revlog.py

CHANGE DETAILS

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -2246,7 +2246,9 @@
         revlog has grown too large to be an inline revlog, it will convert it
         to use multiple index and data files.
         """
-        if not self._inline or (self.start(-2) + self.length(-2)) < _maxinline:
+        tiprev = len(self) - 1
+        if (not self._inline or
+            (self.start(tiprev) + self.length(tiprev)) < _maxinline):
             return
 
         trinfo = tr.find(self.indexfile)
@@ -2260,7 +2262,7 @@
         else:
             # revlog was stripped at start of transaction, use all leftover data
             trindex = len(self) - 1
-            dataoff = self.end(-2)
+            dataoff = self.end(tiprev)
 
         tr.add(self.datafile, dataoff)
 



To: martinvonz, indygreg, #hg-reviewers
Cc: mercurial-devel