src/vs/workbench/contrib/terminal/browser/xterm/xtermTerminal.ts/XtermTerminal/getLongestViewportWrappedLineLength
class XtermTerminal:	getLongestViewportWrappedLineLength(): number {
		let maxLineLength = 0;
		for (let i = this.raw.buffer.active.length - 1; i >= this.raw.buffer.active.viewportY; i--) {
			const lineInfo = this._getWrappedLineCount(i, this.raw.buffer.active);
			maxLineLength = Math.max(maxLineLength, ((lineInfo.lineCount * this.raw.cols) - lineInfo.endSpaces) || 0);
			i = lineInfo.currentIndex;
		}
		return maxLineLength;
	}