tinymce.full.js
function (a, b) {
        var ps = a, pe;

        while (ps) {
          pe = b;

          while (pe && ps != pe) {
            pe = pe.parentNode;
          }

          if (ps == pe) {
            break;
          }

          ps = ps.parentNode;
        }

        if (!ps && a.ownerDocument) {
          return a.ownerDocument.documentElement;
        }

        return ps;
      }
function (a, b) {
        var ps = a, pe;

        while (ps) {
          pe = b;

          while (pe && ps != pe) {
            pe = pe.parentNode;
          }

          if (ps == pe) {
            break;
          }

          ps = ps.parentNode;
        }

        if (!ps && a.ownerDocument) {
          return a.ownerDocument.documentElement;
        }

        return ps;
      }
function ( a , b ) { var ps = a , pe ; while ( ps ) { pe = b ; while ( pe && ps != pe ) { pe = pe . parentNode ; } if ( ps == pe ) { break ; } ps = ps . parentNode ; } if ( ! ps && a . ownerDocument ) { return a . ownerDocument . documentElement ; } return ps ; }
Find the common ancestor of two elements. This is a shorter method than using the DOM Range logic.

@method findCommonAncestor
@param {Element} a Element to find common ancestor of.
@param {Element} b Element to find common ancestor of.
@return {Element} Common ancestor element of the two input elements.
Find the common ancestor of two elements . This is a shorter method than using the DOM Range logic .