message: Copy with selections trying to go to high
diff: @@ -808,7 +808,7 @@ export class TerminalBlock implements Block {
  selectionEnd = this.#selectionStart;
  }
  - const firstRow = selectionStart.y;
  + const firstRow = Math.max(selectionStart.y, 0);
  const lastRow = selectionEnd.y + 1;
  const lineText: string[] = [];
  @@ -842,6 +842,9 @@ export class TerminalBlock implements Block {
  }
  #getLine(row: number): Line {
  + if (row < 0) {
  + return null;
  + }
  if (row < this.#scrollback.length) {
  return this.#scrollback[row];
  }
  