dart2js: Default to an empty set instead of null

dart2js: Default to an empty set instead of null

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/f123fa568de20bf6272bce8bc2456b1f30cc77e5

[asgerf, 2016-01-15 02:05:17]

Description was changed from

==========
dart2js: Return an empty set instead of null.

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors, and should not
surprise the caller by returning null.

BUG=
==========

to

==========
dart2js: Return an empty set instead of null.

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors. We should not
surprise the caller by returning null.

BUG=
==========

[asgerf, 2016-01-15 02:05:28]

Description was changed from

==========
dart2js: Return an empty set instead of null.

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors. We should not
surprise the caller by returning null.

BUG=
==========

to

==========
dart2js: Return an empty set instead of null.

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
==========

[asgerf, 2016-01-15 02:06:13]

Description was changed from

==========
dart2js: Return an empty set instead of null.

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
==========

to

==========
dart2js: Default to an empty set instead of null

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
==========

[asgerf, 2016-01-15 02:07:36]

asgerf@google.com changed reviewers:
+ het@google.com, sigmund@google.com, sra@google.com

[asgerf, 2016-01-15 02:07:36]

A crash can be produced by disabling type propagation and then run on:

class Foo {
	get length {
		try {} finally {}
		return 213;
	}
}

main(args) {
	print(new Foo().length);
}

[Siggi Cherem (dart-lang), 2016-01-15 02:24:06]

lgtm

[asgerf, 2016-01-15 17:29:13]

Description was changed from

==========
dart2js: Default to an empty set instead of null

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
==========

to

==========
dart2js: Default to an empty set instead of null

The set of interceptor classes that can respond to a given selector
depends on which classes are considered instantiated by resolution.
It can therefore be empty even for intercepted selectors.
Do not surprise the caller by returning null.

BUG=
R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/f123fa568de20bf6272bce8bc2456b1f30cc77e5
==========

[asgerf, 2016-01-15 17:29:14]

Committed patchset #1 (id:1) manually as
f123fa568de20bf6272bce8bc2456b1f30cc77e5 (presubmit successful).