Stop flat tree selection canonicalization from using invalid positions

Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
TEST=FrameSelectionTest.SelectInvalidPositionInFlatTreeDoesntCrash

Review-Url: https://codereview.chromium.org/2850443002
Cr-Commit-Position: refs/heads/master@{#467676}
Committed: https://chromium.googlesource.com/chromium/src/+/0cbb9fc2999813a837b8ee0483f77e3879cc25e0

[Xiaocheng, 2017-04-27 06:09:07]

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

[commit-bot: I haz the power, 2017-04-27 06:09:22]

Dry run: CQ is trying da patch.

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

[Xiaocheng, 2017-04-27 06:54:23]

Description was changed from

==========
Stop flat tree selection canonicalization from using invalid positions

BUG=702756, 709872, 712984
==========

to

==========
Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
==========

[Xiaocheng, 2017-04-27 06:54:46]

Description was changed from

==========
Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
==========

to

==========
Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
TEST=FrameSelectionTest.SelectInvalidPositionInFlatTreeDoesntCrash
==========

[Xiaocheng, 2017-04-27 06:55:11]

xiaochengh@chromium.org changed reviewers:
+ yosin@chromium.org

[Xiaocheng, 2017-04-27 06:55:12]

PTAL.

[yosin_UTC9, 2017-04-27 07:02:28]

lgtm w/ a comment to improve test case.

BTW, I feel this is the first time to see this change. ;-)

https://codereview.chromium.org/2850443002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/editing/FrameSelectionTest.cpp (right):

https://codereview.chromium.org/2850443002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/editing/FrameSelectionTest.cpp:343:
Selection().ComputeVisibleSelectionInFlatTree();
nit: Let's have EXPECT_EQ() to compare expected VisibleSelectionInFlatTree for
recording current behavior.

[Xiaocheng, 2017-04-27 07:20:46]

https://codereview.chromium.org/2850443002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/editing/FrameSelectionTest.cpp (right):

https://codereview.chromium.org/2850443002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/editing/FrameSelectionTest.cpp:343:
Selection().ComputeVisibleSelectionInFlatTree();
On 2017/04/27 at 07:02:28, yosin_UTC9 wrote:
> nit: Let's have EXPECT_EQ() to compare expected VisibleSelectionInFlatTree for
recording current behavior.

The expected selection in flat tree should be '|foo'.

I guess it might be changed in the future?

[commit-bot: I haz the power, 2017-04-27 07:52:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-27 07:52:20]

Dry run: This issue passed the CQ dry run.

[Xiaocheng, 2017-04-27 13:28:40]

The CQ bit was checked by xiaochengh@chromium.org

[Xiaocheng, 2017-04-27 13:28:40]

The patchset sent to the CQ was uploaded after l-g-t-m from yosin@chromium.org
Link to the patchset: https://codereview.chromium.org/2850443002/#ps20001
(title: "Add expectation check")

[commit-bot: I haz the power, 2017-04-27 13:28:53]

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, 2017-04-27 15:04:15]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1493299720570170,
"parent_rev": "9afc2bc78b53f5439bce60e2de93f651248f967b", "commit_rev":
"0cbb9fc2999813a837b8ee0483f77e3879cc25e0"}

[commit-bot: I haz the power, 2017-04-27 15:04:27]

Description was changed from

==========
Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
TEST=FrameSelectionTest.SelectInvalidPositionInFlatTreeDoesntCrash
==========

to

==========
Stop flat tree selection canonicalization from using invalid positions

There are some valid DOM positions (*) that do not have corresponding
valid flat tree positions. This patch adds special handling of such
DOM positions, so that when computing VisibleSelectionInFlatTree from
SelectionInDOMTree, such positions are converted to NULL instead of
invalid flat tree positions, so that the renderer does not crash.

(*) If NODE is a direct child of a shadow host but is not distributed
into the flat tree, NODE@BeforeAnchor and NODE@AfterAnchor are valid
Position but invalid PositionInFlatTree. This patch handles these two
kind of positions.

BUG=702756, 709872, 712984
TEST=FrameSelectionTest.SelectInvalidPositionInFlatTreeDoesntCrash

Review-Url: https://codereview.chromium.org/2850443002
Cr-Commit-Position: refs/heads/master@{#467676}
Committed:
https://chromium.googlesource.com/chromium/src/+/0cbb9fc2999813a837b8ee0483f7...
==========

[commit-bot: I haz the power, 2017-04-27 15:04:28]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/0cbb9fc2999813a837b8ee0483f7...