Fix a subtle bug in barback.

Fix a subtle bug in barback.

When a [PhaseOutput.removeListeners] was called, the output was re-added to the [Phase] but its removal event wasn't re-subscribed. This meant that if that output was later removed, the phase got into an inconsistent state where it would perform operations on a removed output.

R=rnystrom@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=27170

[Bob Nystrom, 2013-09-05 00:09:55]

Two nits but LGTM.

https://codereview.chromium.org/23803006/diff/1/pkg/barback/lib/src/phase.dart
File pkg/barback/lib/src/phase.dart (right):

https://codereview.chromium.org/23803006/diff/1/pkg/barback/lib/src/phase.dar...
pkg/barback/lib/src/phase.dart:151:
_outputs[output.output.id].output.whenRemoved.then((_) {
Instead of "_outputs[output.output.id]" here, can you just use "output"?

https://codereview.chromium.org/23803006/diff/1/pkg/barback/test/package_grap...
File pkg/barback/test/package_graph/add_remove_transform_test.dart (right):

https://codereview.chromium.org/23803006/diff/1/pkg/barback/test/package_grap...
pkg/barback/test/package_graph/add_remove_transform_test.dart:256: // Regression
test
Add a "."

[nweiz, 2013-09-05 00:13:09]

Added more detail to the description.

https://codereview.chromium.org/23803006/diff/1/pkg/barback/lib/src/phase.dart
File pkg/barback/lib/src/phase.dart (right):

https://codereview.chromium.org/23803006/diff/1/pkg/barback/lib/src/phase.dar...
pkg/barback/lib/src/phase.dart:151:
_outputs[output.output.id].output.whenRemoved.then((_) {
On 2013/09/05 00:09:55, Bob Nystrom wrote:
> Instead of "_outputs[output.output.id]" here, can you just use "output"?

Done.

https://codereview.chromium.org/23803006/diff/1/pkg/barback/test/package_grap...
File pkg/barback/test/package_graph/add_remove_transform_test.dart (right):

https://codereview.chromium.org/23803006/diff/1/pkg/barback/test/package_grap...
pkg/barback/test/package_graph/add_remove_transform_test.dart:256: // Regression
test
On 2013/09/05 00:09:55, Bob Nystrom wrote:
> Add a "."

Done.

[nweiz, 2013-09-05 00:13:40]

Committed patchset #2 manually as r27170 (presubmit successful).