Create a rectangular selection (Ctrl+click), then resize the terminal so that lines rewrap.

The highlighted selection appears/disappears according to the start and end point's relative positions, and new contents become part of the visual selection (gets wrapped in between existing highlighted stuff) or get removed from there... It's a weird experience, and the actually highlighted part no longer matches the contents of primary/clipboard. (Seems primary/clipboard contains the contents as of when the selection was made.)

I hope you can't crash vte with this :)

Not sure what we could do anything to fix this... maybe completely remove the rectangular selection feature? Does anyone use it?