How to unhide a hidden (obsolete) changeset?

[Michael McNeil Forbes]

How can I unhide a change set?

Consider this example (using the rebase and evolve extensions):

hg init a
cd a
touch A0.txt
hg add
hg com -m "A0"
touch A1.txt
hg add
hg com -m "A1"

hg up 0
touch B0.txt
hg add
hg com -m "B0"

cd ..
hg clone a b
cd b
hg phase -fd 2
hg rebase -s 2 -d 1

# Repo a has:
hg glog -q
@  2:cd21b5c368bd
|
| o  1:06898f86274e
|/
o  0:9bfb043e4c4a

# Repo b has:
hg --hidden glog -q
@  3:063f76a41d36
|
| x  2:cd21b5c368bd
| |
o |  1:06898f86274e
|/
o  0:9bfb043e4c4a

# Now, suppose I decide I do not want to do this, so I strip changesets 3 (and 2 for good measure) and pull again:

cd b
hg strip 3
hg --hidden strip 2
hg pull
hg --hidden glog -q 
o  2:cd21b5c368bd
|
| @  1:06898f86274e
|/
o  0:9bfb043e4c4a

# So far so good, but if I make changeset 2 draft again to edit it, it is still hidden
hg phase -fd 2
hg --hidden glog -q 
x  2:cd21b5c368bd
|
| @  1:06898f86274e
|/
o  0:9bfb043e4c4a

# How do I unhide changeset 2 so that repo b behaves like a repo a?

Michael.