bookmarks: Avoid unconditional forwarding of bookmarks for the null revision
This patch fixes the following minor problem:
% hg bookmark -r null test
% hg bookmarks
test -1:000000000000
[...]
% hg commit
% hg bookmarks
* test 17:861ce7a241f9
That is: Bookmarks referring to the null revision are always forwarded
to the current revision.
import os
from mercurial import hg, ui
u = ui.ui()
repo = hg.repository(u, 'test1', create=1)
os.chdir('test1')
# create 'foo' with fixed time stamp
f = file('foo', 'w')
f.write('foo\n')
f.close()
os.utime('foo', (1000, 1000))
# add+commit 'foo'
repo.add(['foo'])
repo.commit(text='commit1', date="0 0")
print "workingfilectx.date =", repo[None]['foo'].date()