moby: memory leak in buffer grow

Hi! I’ve experienced problem with memory leak which looks pretty simular to #8084 .

docker 1.3.0

go tool pprof on heap looks like:

Total: 8659.9 MB
     0.0   0.0%   0.0%   8658.9 100.0% runtime.gosched0
     0.0   0.0%  99.8%   8638.3  99.7% github.com/docker/docker/daemon.func·006
     4.5   0.1%   0.1%   8643.9  99.8% io.Copy
     0.0   0.0%  99.8%   8637.8  99.7% github.com/docker/docker/engine.(*Output).Write
     0.0   0.0%   0.1%   8639.9  99.8% bytes.(*Buffer).Write
     0.0   0.0%   0.1%   8639.9  99.8% bytes.(*Buffer).grow
  8639.9  99.8%  99.8%   8639.9  99.8% bytes.makeSlice

I don’t know how to reproduce it with simple example but if you need any additional information I can gather it from out production project.