Fix pub to close connection to dartlang.org when it's done downloading

Fix pub to close connection to dartlang.org when it's done downloading

See bug http://dartbug.com/4857
fixes: http://dartbug.com/4856

Committed: https://code.google.com/p/dart/source/detail?r=11714

[Jennifer Messerly, 2012-08-31 18:07:06]

This is the fix Mads suggested. I tested this out, with this fix, pub no longer
hangs on "pub update"

[Bob Nystrom, 2012-08-31 18:30:07]

LGTM!

[Søren Gjesse, 2012-09-03 07:03:15]

I suggest that a singleton HttpClient is used throughout the application and
that that instance is shutdown when the application is existing. Performing a
shutdown after each successful request disables the possibility for using
persistent connections. Also in an error situation shutdown is not called which
might also cause undesired behavior.

[Bob Nystrom, 2012-09-04 21:59:13]

On 2012/09/03 07:03:15, Søren Gjesse wrote:
> I suggest that a singleton HttpClient is used throughout the application and
> that that instance is shutdown when the application is existing. Performing a
> shutdown after each successful request disables the possibility for using
> persistent connections. Also in an error situation shutdown is not called
which
> might also cause undesired behavior.

Thanks for the suggestion. That's a good point.

I'll be poking at this code again soon (to add better timeout support), so I'll
try out using a single HttpClient then.