8341281: Root TreeItem with null value breaks TreeTableView

[Ziad-Mid]

When the Root TreeItem is set to null, need to relayout to show the children items

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Progress

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Issue

• JDK-8341281: Root TreeItem with null value breaks TreeTableView (Bug - P4)

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[bridgekeeper]

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[openjdk]

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[andy-goryachev-oracle]

Good job, the fix seems to be working.

You can also try using the monkey tester to test various scenarios, I've updated it to include null values for root in the TreeTableViewPage and TreeViewPage
https://github.com/andy-goryachev-oracle/MonkeyTest

Could you also come up with a unit test(s) for the fix, that will fail in the master branch but pass with the fix, preferably a headless test?

Once you have the test, you can make this PR ready for review (RFR).

[andy-goryachev-oracle]

please ignore the failing pre-submit Windows test - we have an ongoing issue with the github actions (GHA), see https://bugs.openjdk.org/browse/JDK-8354337

[mlbridge]

Webrevs

• 00: Full (c80550e4)

[andy-goryachev-oracle]

if you merge the latest master branch it'll get rid of the build error on windows.

[kevinrushforth]

Reviewers: @andy-goryachev-oracle @arapte

/reviewers 2

[openjdk]

@kevinrushforth
The total number of required reviews for this PR (including the jcheck configuration and the last /reviewers command) is now set to 2 (with at least 1 Reviewer, 1 Author).