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.
#!/bin/sh
rm -rf a
hg init a
cd a
echo a > a
hg ci -Am0
hg tag t1 # 1
hg tag --remove t1 # 2
hg co 1
hg tag -r0 t1
hg tags