The new block looks like this:

```js
        if (oldValue !== newValue) {
            this._currentOptions[prefName] = newValue;
            
            if (prefName === USE_TAB_CHAR) {
                this._codeMirror.setOption("indentUnit", newValue === true ?
                                           this._currentOptions[TAB_SIZE] :
                                           this._currentOptions[SPACE_UNITS]
                                          );
            } else if (prefName === STYLE_ACTIVE_LINE) {
                this._updateStyleActiveLine();
            } else {
                // Set the CodeMirror option as long as it's not a change
                // that is in conflict with the useTabChar setting.
                var useTabChar = this._currentOptions[USE_TAB_CHAR];
                if ((useTabChar && prefName === SPACE_UNITS) || 
                    (!useTabChar && prefName === TAB_SIZE)) {
                    return;
                }
                
                this._codeMirror.setOption(cmOptions[prefName], newValue);
            }
            
            $(this).triggerHandler("optionChange", [prefName, newValue]);
        }
```