update: fix bug when update tries to modify folder symlink...
update: fix bug when update tries to modify folder symlink
In 1e4512eac59e0114bc60ecbcdc4157fc0fa0439d, I introduced a new bug:
when a symlink points to a folder in commit A and to another folder
in commit B, while updating from A to B, Mercurial will try to use
removedir on this symlink, which will fail. This is a very bad bug,
since it basically renders symlinks to folders unusable in repos.
Added test case fails without a fix and passes with it.
