message: Fixes where upstream doc was missing meta
diff: @@ -98,6 +98,7 @@ module.exports = class DocumentContext {
  }
  async updateDocumentMeta(meta) {
  + this.upstreamDoc.data.meta = merge({}, this.upstreamDoc.data.meta, meta);
  await this.pristineDoc();
  if (!this._pristine || !this._pristine.data) { return; }
  