Function maybeUpdateRectForZooming

external/.scrollLibs.js:3852–3859

(measure, rect)

  // Work around problem with bounding client rects on ranges being
  // returned incorrectly when zoomed on IE10 and below.
  function maybeUpdateRectForZooming(measure, rect) {
    if (!window.screen || screen.logicalXDPI == null || screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure)) {
      return rect
    }
    var scaleX = screen.logicalXDPI / screen.deviceXDPI
    var scaleY = screen.logicalYDPI / screen.deviceYDPI
    return { left: rect.left * scaleX, right: rect.right * scaleX, top: rect.top * scaleY, bottom: rect.bottom * scaleY }
  }

  function clearLineMeasurementCacheFor(lineView) {
    if (lineView.measure) {