[PATCH 1 of 2] strip: hold wlock for entire duration

[Siddharth Agarwal]

On 11/18/2013 10:23 AM, Siddharth Agarwal wrote:
> # HG changeset patch
> # User Siddharth Agarwal <sid0 at fb.com>
> # Date 1384793839 28800
> #      Mon Nov 18 08:57:19 2013 -0800
> # Node ID ff06af69dbaf102c340ffb459907a8fd73b509f5
> # Parent  a53b8c6609e57129db9ed90ce4630bdbe3b0c72d
> strip: hold wlock for entire duration
>
> Previously, we'd acquire and release the wlock several times. This meant that
> other hg processes could come in and change state. Instead of that, retain the
> wlock for the entire duration of the strip.

For this patch, I decided to ruin blame because there wasn't any blame
to begin with.

Like the histedit patch, this series also likely belongs on stable.