Shift+Del does not copy the deleted text #2719

When pressing Shift+Del in the commit message text box, the selected text is deleted but not copied to clipboard. This can be reproduced as follows:

1. Type some text in the commit message window. Select some part of it.
2. Press Shift+Del. The selected text is deleted.
3. Press Shift+Ins. Either nothing is inserted or whatever was present on the clipboard before step 2 is inserted.

This seems to be specific to the Shift+Del hotkey. E.g. Ctrl+X works as intended. Also, Ctrl+Ins also works (i.e. it copies the selected text to clipboard), and Shift+Ins also works.

Kubuntu 24.04, KDE, X11, SourceGit 2026.19, 2026.20.