Fix bug in subscription handling in mime package

Fix bug in subscription handling in mime package

The parser now parses each received chunk to the end no matter what the
paused state of the part stream is. This will add data to the part
stream controller before it is even listened on, but only the data already
received from the original input stream.

Not trying to stop the parsing on a received chunk when the part stream
is paused makes the code simpler to reason about.

The two added tests modes failed without this change. Either by hanging
or by hitting an exception trying to invoke the getter 'length' on null.

R=kustermann@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=43835

[kustermann, 2015-02-17 17:08:03]

lgtm - provided that synchronous StreamControllers will buffer the data if they
are paused (which I don't know for sure).

https://codereview.chromium.org/934763004/diff/1/pkg/mime/test/mime_multipart...
File pkg/mime/test/mime_multipart_transformer_test.dart (right):

https://codereview.chromium.org/934763004/diff/1/pkg/mime/test/mime_multipart...
pkg/mime/test/mime_multipart_transformer_test.dart:73: });
You don't need a completer here. Doing futures.add(new Future(() {...}))` should
work.

[Søren Gjesse, 2015-02-18 07:24:30]

New patchsets have been uploaded after l-g-t-m from kustermann@google.com

[Søren Gjesse, 2015-02-18 07:27:18]

All (non-broadcast) StreamControllers buffer until the subscriber is registered.

https://codereview.chromium.org/934763004/diff/1/pkg/mime/test/mime_multipart...
File pkg/mime/test/mime_multipart_transformer_test.dart (right):

https://codereview.chromium.org/934763004/diff/1/pkg/mime/test/mime_multipart...
pkg/mime/test/mime_multipart_transformer_test.dart:73: });
On 2015/02/17 17:08:03, kustermann wrote:
> You don't need a completer here. Doing futures.add(new Future(() {...}))`
should
> work.

Done.

[Søren Gjesse, 2015-02-18 07:27:55]

Committed patchset #2 (id:20001) manually as 43835 (presubmit successful).