message: dont format empty ranges
diff: @@ -434,6 +434,9 @@ export default class BasicMessageEditor extends React.Component {
  this._editorRef,
  this.props.model,
  document.getSelection());
  + if (range.length === 0) {
  + return;
  + }
  switch (action) {
  case "bold":
  formatInline(range, "**");
  