fix #30427, casting tearoffs to the wrong type

fix #30427, casting tearoffs to the wrong type

apparently these aren't used much, since the previous cast could never succeed.

R=paulberry@google.com

Committed: https://github.com/dart-lang/sdk/commit/1ac2725a1b6142ec6b45a1859947e05a56eb79f7

[Jennifer Messerly, 2017-08-11 22:06:06]

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

[Jennifer Messerly, 2017-08-11 22:06:08]

This fixes the bug. I've also commented on how to fix the other bug if we choose
the "cast tearoffs eagerly" approach :)

https://codereview.chromium.org/2998873002/diff/1/pkg/analyzer/lib/src/task/s...
File pkg/analyzer/lib/src/task/strong/checker.dart (right):

https://codereview.chromium.org/2998873002/diff/1/pkg/analyzer/lib/src/task/s...
pkg/analyzer/lib/src/task/strong/checker.dart:913: var expectedType =
member.returnType;
If we wanted to fix other covariant tearoffs by casting at tearoff point, we
could do it here.

instead of using ".returnType" on both sides, just evaluate the full type:


var worstCaseType = _lookUpMember(classLowerBound, member).type;
var expectedType = member.type

var isMethod = member is MethodElement;
var isCall = node is MethodInvocation;
var isTearOff = isMethod && !isCall;
if (!isTearOff) {
  // For non-tearoff, we're only interested in the return type.
  expectedType = expectedType.returnType;
  worstCaseType = worstCaseType.returnType;
}

... rest of code as normal & revert the changes I'm making below, because
tearoffs won't be special anymore and "expectedType" will mean the right thing
:)

[Paul Berry, 2017-08-11 22:28:17]

lgtm

lgtm, thanks!

[Jennifer Messerly, 2017-08-11 22:47:44]

Description was changed from

==========
fix #30427, casting tearoffs to the wrong type

apparently these aren't used much, since the previous cast could never succeed.
==========

to

==========
fix #30427, casting tearoffs to the wrong type

apparently these aren't used much, since the previous cast could never succeed.

R=paulberry@google.com

Committed:
https://github.com/dart-lang/sdk/commit/1ac2725a1b6142ec6b45a1859947e05a56eb79f7
==========

[Jennifer Messerly, 2017-08-11 22:47:46]

Committed patchset #1 (id:1) manually as
1ac2725a1b6142ec6b45a1859947e05a56eb79f7 (presubmit successful).