Function updateGutterSpace

static/editor.md/lib/codemirror/lib/codemirror.js:321–324

(cm)

  }

  function updateGutterSpace(cm) {
    var width = cm.display.gutters.offsetWidth;
    cm.display.sizer.style.marginLeft = width + "px";
  }

  // Compute the character length of a line, taking into account
  // collapsed ranges (see markText) that might hide parts, and join