Function visualLine

external/.scrollLibs.js:1495–1501

(line)

  // visual line. This finds the start of the visual line that the
  // given line is part of (usually that is the line itself).
  function visualLine(line) {
    var merged
    while ((merged = collapsedSpanAtStart(line))) {
      line = merged.find(-1, true).line
    }
    return line
  }

  function visualLineEnd(line) {
    var merged