message: bandaid end of doc rendering; full fix required
diff: @@ -2089,6 +2089,9 @@ function renderFlow(layoutContext: ILayoutContext, deferWhole = false): IRenderO
  if (currentPos < (totalLength - 1)) {
  renderPG(curPGMarker, currentPos, indentWidth, indentSymbol, contentWidth);
  currentPos = curPGMarkerPos + curPGMarker.cachedLength;
  + if (currentPos>=(totalLength-1)) {
  + break;
  + }
  segoff = getContainingSegment(flowView, currentPos);
  if (segoff.segment.getType() === SharedString.SegmentType.Marker) {
  let marker = <SharedString.Marker>segoff.segment;
  @@ -2103,6 +2106,8 @@ function renderFlow(layoutContext: ILayoutContext, deferWhole = false): IRenderO
  if (lastLineDiv) {
  lastLineDiv.lineEnd = curPGMarkerPos;
  }
  + } else {
  + break;
  }
  }
  } while (layoutContext.viewport.remainingHeight() >= docContext.defaultLineDivHeight);
  