Previously, `docker logs` (and by extension, `docker service logs`) had
an error in the way they returned errors that occurred after a stream
had already been started. Specifically, the errors were added verbatim
to the HTTP response, which caused StdCopy to fail with an esoteric
error. This change updates StdCopy to accept errors from the source
stream and then return those errors when copying to the destination
stream.
Signed-off-by: Drew Erny <drew.erny@docker.com>
Upstream-commit: f19b0d72d1234c2bf4d85f7c1a4916b7b85b97b0
Component: engine
f9c823322f