[MERGE][#144421][#144300] Use write lock in log and status with '-r branch:URL'

[Alexander Belchenko]

Lukáš Lalinský пишет:
> This patch replaces lock_read with lock_write in log and status if the
> 'branch:' revision specifier is used. I realize it would be probably
> better to just get rid of the implicit fetching, but I think fixing the
> lock is good enough as an interim solution.

Today I discover that bzr diff -rbranch:XXX works, but bzr status -rbranch:XXX
is not. I found workaround to use `bzr diff -rbranch:XXX | grep '^==='` instead
of status.

Why status does not work? What makes status so special that it can't work? Why diff can?
Could anybody shed some light on this? Looking at this patch I don't understand
why for write lock needed.