ValueSerializer: Distinguish between 'undefined' and an absent property.

ValueSerializer: Distinguish between 'undefined' and an absent property.

Dealing with this case requires a wire format change. It is possible that an
element can be absent even in an array where the dense format was chosen
(because the array initially had no holes), if the elements are modified while
they are being serialized. In this case, a new tag for the "hole" is emitted.

The logic to treat undefined in dense arrays as an absent property is restricted
to versions of the wire format that this tag did not exist.

BUG=chromium:686159, chromium:665820
Review-Url: https://codereview.chromium.org/2660093002
Cr-Original-Commit-Position: refs/heads/master@{#42784}
Committed: https://chromium.googlesource.com/v8/v8/+/dc85f4c8338c1c824af4f7ee3274dc9f95d14e49
Review-Url: https://codereview.chromium.org/2660093002
Cr-Commit-Position: refs/heads/master@{#42800}
Committed: https://chromium.googlesource.com/v8/v8/+/6f1639ed16a21b2395b98e8c61de268a275ee920

[jbroman, 2017-01-28 22:39:20]

The CQ bit was checked by jbroman@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-28 22:39:30]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jbroman, 2017-01-28 23:55:42]

The CQ bit was unchecked by jbroman@chromium.org

[jbroman, 2017-01-28 23:56:38]

jbroman@chromium.org changed reviewers:
+ jkummerow@chromium.org

[jbroman, 2017-01-28 23:56:39]

This also makes the
external/wpt/workers/interfaces/DedicatedWorkerGlobalScope/postMessage/structured-clone-message.html
layout test pass; I'll send a CL to enable it on the Blink side after this
lands.

[Jakob Kummerow, 2017-01-30 03:11:38]

LGTM with a nit

https://codereview.chromium.org/2660093002/diff/1/src/value-serializer.cc
File src/value-serializer.cc (right):

https://codereview.chromium.org/2660093002/diff/1/src/value-serializer.cc#new...
src/value-serializer.cc:544: // TODO(jbroman): Distinguish between undefined and
a hole (this can happen
nit: you can drop this :-)

[jbroman, 2017-01-30 18:08:28]

The CQ bit was checked by jbroman@chromium.org

[jbroman, 2017-01-30 18:08:28]

The patchset sent to the CQ was uploaded after l-g-t-m from
jkummerow@chromium.org
Link to the patchset: https://codereview.chromium.org/2660093002/#ps20001
(title: "remove TODO")

[jbroman, 2017-01-30 18:08:30]

https://codereview.chromium.org/2660093002/diff/1/src/value-serializer.cc
File src/value-serializer.cc (right):

https://codereview.chromium.org/2660093002/diff/1/src/value-serializer.cc#new...
src/value-serializer.cc:544: // TODO(jbroman): Distinguish between undefined and
a hole (this can happen
On 2017/01/30 at 03:11:38, Jakob Kummerow wrote:
> nit: you can drop this :-)

Done!

[commit-bot: I haz the power, 2017-01-30 18:08:37]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-30 18:43:38]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1485799708326400,
"parent_rev": "7438304229b57a88f0b9857922f806af32718a80", "commit_rev":
"dc85f4c8338c1c824af4f7ee3274dc9f95d14e49"}

[commit-bot: I haz the power, 2017-01-30 18:43:44]

Description was changed from

==========
ValueSerializer: Distinguish between 'undefined' and an absent property.

Dealing with this case requires a wire format change. It is possible that an
element can be absent even in an array where the dense format was chosen
(because the array initially had no holes), if the elements are modified while
they are being serialized. In this case, a new tag for the "hole" is emitted.

The logic to treat undefined in dense arrays as an absent property is restricted
to versions of the wire format that this tag did not exist.

BUG=chromium:686159,chromium:665820
==========

to

==========
ValueSerializer: Distinguish between 'undefined' and an absent property.

Dealing with this case requires a wire format change. It is possible that an
element can be absent even in an array where the dense format was chosen
(because the array initially had no holes), if the elements are modified while
they are being serialized. In this case, a new tag for the "hole" is emitted.

The logic to treat undefined in dense arrays as an absent property is restricted
to versions of the wire format that this tag did not exist.

BUG=chromium:686159,chromium:665820

Review-Url: https://codereview.chromium.org/2660093002
Cr-Commit-Position: refs/heads/master@{#42784}
Committed:
https://chromium.googlesource.com/v8/v8/+/dc85f4c8338c1c824af4f7ee3274dc9f95d...
==========

[commit-bot: I haz the power, 2017-01-30 18:43:45]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/dc85f4c8338c1c824af4f7ee3274dc9f95d...

[Michael Achenbach, 2017-01-30 19:35:11]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/2667553003/ by machenbach@chromium.org.

The reason for reverting is: Seems to break layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/bui...

https://github.com/v8/v8/wiki/Blink-layout-tests.

[jbroman, 2017-01-31 01:52:45]

The CQ bit was checked by jbroman@chromium.org

[jbroman, 2017-01-31 01:52:46]

Fixed Blink-side test, v8_linux_blink_rel passes. Re-CQing.

[commit-bot: I haz the power, 2017-01-31 01:52:48]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-31 01:54:27]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1485827565033120,
"parent_rev": "c0b1bcba2f33565201eaf3148b10dbe5d4c9231a", "commit_rev":
"6f1639ed16a21b2395b98e8c61de268a275ee920"}

[commit-bot: I haz the power, 2017-01-31 01:54:31]

Description was changed from

==========
ValueSerializer: Distinguish between 'undefined' and an absent property.

Dealing with this case requires a wire format change. It is possible that an
element can be absent even in an array where the dense format was chosen
(because the array initially had no holes), if the elements are modified while
they are being serialized. In this case, a new tag for the "hole" is emitted.

The logic to treat undefined in dense arrays as an absent property is restricted
to versions of the wire format that this tag did not exist.

BUG=chromium:686159,chromium:665820

Review-Url: https://codereview.chromium.org/2660093002
Cr-Commit-Position: refs/heads/master@{#42784}
Committed:
https://chromium.googlesource.com/v8/v8/+/dc85f4c8338c1c824af4f7ee3274dc9f95d...
==========

to

==========
ValueSerializer: Distinguish between 'undefined' and an absent property.

Dealing with this case requires a wire format change. It is possible that an
element can be absent even in an array where the dense format was chosen
(because the array initially had no holes), if the elements are modified while
they are being serialized. In this case, a new tag for the "hole" is emitted.

The logic to treat undefined in dense arrays as an absent property is restricted
to versions of the wire format that this tag did not exist.

BUG=chromium:686159,chromium:665820

Review-Url: https://codereview.chromium.org/2660093002
Cr-Original-Commit-Position: refs/heads/master@{#42784}
Committed:
https://chromium.googlesource.com/v8/v8/+/dc85f4c8338c1c824af4f7ee3274dc9f95d...
Review-Url: https://codereview.chromium.org/2660093002
Cr-Commit-Position: refs/heads/master@{#42800}
Committed:
https://chromium.googlesource.com/v8/v8/+/6f1639ed16a21b2395b98e8c61de268a275...
==========

[commit-bot: I haz the power, 2017-01-31 01:54:32]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/6f1639ed16a21b2395b98e8c61de268a275...