Function clipCursorToContent

static/js/codemirror/keymap/vim.js:1400–1406

* Clips cursor to ensure that line is within the buffer's range * If includeLineBreak is true, then allow cur.ch == lineLength.

(cm, cur, includeLineBreak)

     * If includeLineBreak is true, then allow cur.ch == lineLength.
     */
    function clipCursorToContent(cm, cur, includeLineBreak) {
      var line = Math.min(Math.max(cm.firstLine(), cur.line), cm.lastLine() );
      var maxCh = lineLength(cm, line) - 1;
      maxCh = (includeLineBreak) ? maxCh + 1 : maxCh;
      var ch = Math.min(Math.max(0, cur.ch), maxCh);
      return { line: line, ch: ch };
    }
    // Merge arguments in place, for overriding arguments.
    function mergeArgs(to, from) {
      for (var prop in from) {