Description:
Seen with the KDE5 VCL, don't know if other VCL plugins show the same issue.

Have a calc spreadsheet where a row is made of cells with long texts in them (text spanning multiple lines with linebreaks).

Selecting these cells is extra slow in LibO6.2: you see an evident delay between the mouse click (for the selection) and the visual feedback (cell background changing color).

If you try to select multiple contiguous cells (e.g. select one cell and then press SHIFT and click on another cell), then LIBO6.2 becomes /extremely slow/ and seems to hang. In fact it does not hang. If you leave enough time to it (even minutes), then it does what it should.

At the same time on the terminal you may see tons of "QXcbClipboard: SelectionRequest too old" and CPU usage goes high (but not super-high).

Makes calc on 6.2 sort of not usable for this case.

Steps to Reproduce:
See description

Actual Results:
See description

Expected Results:
See description


Reproducible: Always


User Profile Reset: No



Additional Info:
[Information automatically included from LibreOffice]
Locale: en-US
Module: SpreadsheetDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes