[PATCH 2 of 8 STABLE] debugrevlog: add empty commit

[timeless]

# HG changeset patch
# User timeless <timeless at mozdev.org>
# Date 1454287191 0
#      Mon Feb 01 00:39:51 2016 +0000
# Branch stable
# Node ID 9f98a0cc6fa3c19af557766eeed16e06227ed4d1
# Parent  8bb0dcb854c1bab3a92842af9010e5b4e4c8dc36
debugrevlog: add empty commit

diff --git a/tests/test-debugcommands.t b/tests/test-debugcommands.t
--- a/tests/test-debugcommands.t
+++ b/tests/test-debugcommands.t
@@ -23,6 +23,14 @@
   $ echo a > a
   $ hg ci -Am adda
   adding a
+  $ hg commit --config ui.allowemptycommit=True -m 'empty'
+  $ hg debugrevlog -c -d
+  # rev p1rev p2rev start   end deltastart base   p1   p2 rawsize totalsize compression heads chainlen
+      0    -1    -1     0    58          0    0    0    0      57        57           0     1        0
+      1     0    -1    58    87          0    0    0    0      56       113           1     1        1
+  $ hg rollback
+  repository tip rolled back to revision 0 (undo commit)
+  working directory now based on revision 0
   $ hg debugrevlog -m
   format : 1
   flags  : inline, generaldelta