fix: prevent exception when dropping row on header with TextField (va…

[pablorodriguesb]

…adin#7689)

Description

Please list all relevant dependencies in this section and provide summary of the change, motivation and context.

Fixes #7689

Type of change

• Bugfix
• Feature

Checklist

• I have read the contribution guide: https://vaadin.com/docs/latest/contributing/overview
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.
• I have not completed some of the steps above and my pull request can be closed immediately.

Additional for Feature type of change

• Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

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[pablorodriguesb]

Hi! I have formatted the code locally (mvn spotless:apply) and all looks correct on my side.
It seems the failed checks are due to CI permissions for external contributors ("user is not a flow-components team member").
SThank you!

[vursen]

Thanks for your contribution. It seems like the root issue is that Grid allows rows to be dropped onto header rows, so addressing that might actually be a better solution. Receiving an incorrect DropEvent seems more like a symptom.

[trendelmann]

...so it is not yet public in any release?

[trendelmann]

We as a customer / consumer of YOUR grid cannot address here anything - sorry. The Vaadin grid try to construct the DropEvent, that in turn fails. The DropEvent completes the drag-n-drop sequence, and we cannot do anything in between.
So we do NOT "Receiving an incorrect DropEvent...", we get nothing - because the creation of the DropEvent parameter failed completely and breaks the sequence mentioned.

So please fix that anyway and make it into a upcoming release, please