from a new repo with attic enabled:
... do something
hg shelve
... fails
hg shelve patch1
... do something
hg shelve
... should fail
hg shelve patch2
hg unshelve
hg shelve
... should pass (overwriting patch 2)
hg unshelve patch1
... do some work
hg shelve
... should pass (overwriting patch 1)

1.
from a new repo with attic enabled:
... do something
hg shelve
... fails
hg shelve patch1
... do something
hg shelve
... should fail
hg shelve patch2
hg attic
... prints "patch1, patch2"

or
2.
from a new repo with attic enabled:
... do something
hg shelve
... prints "warning: no name provided, used patch1"
hg shelve mypatch1
... do something
hg shelve
... prints "warning: no name provided, used patch2"
hg shelve mypatch2
hg attic
... prints "mypatch1, mypatch2, patch1, patch2"

from a new repo with attic enabled:
... do something
hg shelve
... adds patch1
... do something
hg shelve
... adds patch2
... do something
hg shelve
... adds patch3
... do something
hg shelve --refresh
... adds newchanges to patch3
hg attic
patch1
patch2
patch3
hg attic -c
... current patch information
hg attic -p patch2
... patch2 information
hg unshelve
... gets back patch3 changes to working dir
hg unshelve
... fail, needs patch name? or get back patch2
hg unshelve patch1
... do some work