[PATCH 1 of 2] hghave: avoid a deadlock reading the child process's output

[Yuya Nishihara]

On Thu, 31 May 2018 22:35:00 -0400, Matt Harbison wrote:
> # HG changeset patch
> # User Matt Harbison <matt_harbison at yahoo.com>
> # Date 1527819107 14400
> #      Thu May 31 22:11:47 2018 -0400
> # Node ID 0de423ecd560edaa0f1eb25cc265c3b2e8caf0f0
> # Parent  7fa3408f83ef1a04e2d23ab6f8498833b450e589
> hghave: avoid a deadlock reading the child process's output

Queued for stable, thanks.