fix #26552, improve null coalescing inference

fix #26552, improve null coalescing inference

R=leafp@google.com

Committed: https://github.com/dart-lang/sdk/commit/8026c9509c1d20404fef6c12a8e3ed06e07a6271

[Jennifer Messerly, 2016-08-04 20:46:05]

jmesserly@google.com changed reviewers:
+ leafp@google.com

[Jennifer Messerly, 2016-08-04 20:46:05]

Seems kind of reasonable. WDYT?

[Leaf, 2016-08-04 22:26:44]

lgtm

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/resolver.dart (right):

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/resolver.dart:6960: // Do we need to do thiat?
Might even be worth filtering out dynamic in setType.

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/test/src/task/...
File pkg/analyzer/test/src/task/strong/inferred_type_test.dart (right):

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/test/src/task/...
pkg/analyzer/test/src/task/strong/inferred_type_test.dart:3620: // Regression
test for https://github.com/dart-lang/sdk/issues/26552
Can you put a case in here to test for when we do have a context type to make
sure that doesn't regress in the future?  Unless there's already a separate test
for that.

[Jennifer Messerly, 2016-08-04 22:57:49]

Thanks!

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/resolver.dart (right):

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/resolver.dart:6960: // Do we need to do thiat?
On 2016/08/04 22:26:44, Leaf wrote:
> Might even be worth filtering out dynamic in setType.

Oh! good idea. I'll move the TODO and do it in a follow up. (I think it changes
some of our "inferred type here" markings. It actually seems to expose a bug
where we are doing inference and not marking. But we didn't notice because the
downwards "dynamic" counts as inference...)

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/test/src/task/...
File pkg/analyzer/test/src/task/strong/inferred_type_test.dart (right):

https://codereview.chromium.org/2217693003/diff/1/pkg/analyzer/test/src/task/...
pkg/analyzer/test/src/task/strong/inferred_type_test.dart:3620: // Regression
test for https://github.com/dart-lang/sdk/issues/26552
On 2016/08/04 22:26:44, Leaf wrote:
> Can you put a case in here to test for when we do have a context type to make
> sure that doesn't regress in the future?  Unless there's already a separate
test
> for that.

Done.

[Jennifer Messerly, 2016-08-05 14:19:51]

Description was changed from

==========
fix #26552, improve null coalescing inference
==========

to

==========
fix #26552, improve null coalescing inference

R=leafp@google.com

Committed:
https://github.com/dart-lang/sdk/commit/8026c9509c1d20404fef6c12a8e3ed06e07a6271
==========

[Jennifer Messerly, 2016-08-05 14:19:52]

Committed patchset #2 (id:20001) manually as
8026c9509c1d20404fef6c12a8e3ed06e07a6271 (presubmit successful).