[Chrome] /tests/plugins/enter/list - one of tests throws error "Discontiguous selection is not supported. "

[Piotrek Koszuliński]

Run: ​http://tests.ckeditor.dev:1030/tests/plugins/enter/list One of tests throw:

Discontiguous selection is not supported. selection.js:1974
CKEDITOR.dom.selection.selectRanges selection.js:1974
CKEDITOR.dom.range.select selection.js:1014
CKEDITOR.plugins.enterkey.enterBlock plugin.js:392
enter plugin.js:525
editor.addCommand.exec plugin.js:13
exec command.js:52
CKEDITOR.tools.extend.execCommand editor.js:825
assertEnter list:92

Tests pass, but we're apparently trying to do something incorrect.

[Artur Delura]

​https://github.com/timdown/rangy/commit/fc34ad18f05d89e3d979f07d30be59f6c590ddd3 ​https://code.google.com/p/chromium/issues/detail?id=399791

[Piotrek Koszuliński]

Thanks Artur for finding this.

[Artur Delura]

Changes in ​branch:t/12257. Simply when there is added range into relection while already exists one Chrome shows warning. To prevent this situation we have to clean reanges before adding one. In ​git:ce84cc4 I added wrapper function (this commit is optional).

[Piotrek Koszuliński]

This patch is incorrect and tests very quickly prove that. You should run tests related to the change on at least Chrome, Firefox and one of IEs before putting a branch on review.

The reason why this patch is incorrect is that Firefox handles multi-range selections, so it's not correct to remove all ranges between adding a new one.

[Piotrek Koszuliński]

The thing that we must check is why selectRanges( ) is called with multiple ranges in ​http://tests.ckeditor.dev:1030/tests/plugins/enter/list, because it doesn't seem to make sense.

Note - selection.removeAllRanges() is called at the beginning of selection.selectRanges(), so if only one range was passed, then there's no chance of creating the discontiguous selection.

[Piotrek Koszuliński]

It turns out that this issue was fixed by #12630. So there really was some reason deep under the ground.