message: allow user to break out of blockquote/etc by hitting enter twice
diff: @@ -990,15 +990,29 @@ export default class MessageComposerInput extends React.Component {
  return change.insertText('\n');
  }
  - if (this.state.editorState.blocks.some(
  - block => ['code', 'block-quote', 'list-item'].includes(block.type)
  - )) {
  + const editorState = this.state.editorState;
  +
  + let inBlock = false;
  + let inEmptyBlock = false;
  +
  + for (const block of editorState.blocks) {
  + if (['code', 'block-quote', 'list-item'].includes(block.type)) {
  + inBlock = true;
  + if (block.text === '') {
  + inEmptyBlock = true;
  + }
  + break;
  + }
  + }
  +
  + if (inEmptyBlock) {
  + // allow the user to cancel empty block by hitting return, useful in conjunction with below `inBlock`
  + return change.setBlocks(DEFAULT_NODE);
  + } else if (inBlock) {
  // allow the user to terminate blocks by hitting return rather than sending a msg
  return;
  }
  - const editorState = this.state.editorState;
  -
  let contentText;
  let contentHTML;
  