Possible race in DomRenderer: Cannot read properties of undefined (reading 'replaceChildren')

[connor4312]

1. In VS Code OSS, check out 59d8f2bd9c6
2. Run a couple of unit tests, with the selfhost test provider for example, and open the TestResults view
3. Click on the two top-level test result nodes to switch terminals.
4. Notice you'll eventually get an error in the console. Her
   e's the debug state, it looks like there might be an off-by-one error where y references a row element that does not yet exist

[Tyriar]

We fixed a similar problem recently, we probably need to clamp start/end to ensure they're valid.