cmdstate: avoid setting a default argument to a mutable object (`{}`)
If there's ever more than one cmdstate for the lifetime of the process, this can
cause surprising behavior where the later cmdstates pick up options from the
earlier ones.
I've not seen any evidence this is actually causing any issues, but it's subtle
enough that it should probably be fixed to help save significant debugging time
later.
-------------------------
Evolve Commands Reference
-------------------------
.. highlight:: none
amend
-----
.. hghelp:: amend
evolve
------
.. hghelp:: evolve
fold
----
.. hghelp:: fold
metaedit
--------
.. hghelp:: metaedit
next
----
.. hghelp:: next
obslog
------
.. hghelp:: obslog
pdiff
-----
.. hghelp:: pdiff
previous
--------
.. hghelp:: previous
prune
-----
.. hghelp:: prune
pstatus
-------
.. hghelp:: pstatus
split
-----
.. hghelp:: split
touch
-----
.. hghelp:: touch
uncommit
--------
.. hghelp:: uncommit