Block content located in a table cell breaks the table when rendering to CommonMark Markdown 1.2

When rendering to markdown/1.2, some block content located in a table cell is rendered on several lines, which breaks the table since Markdown table rows must fit on a single line. For example:

• a standalone macro producing several lines, e.g. in xwiki/2.1:

  |=a|=b
  |x|(((
  {{info}}
  hello
  {{/info}}
  )))
  

• a quotation containing several blocks, e.g. <td><blockquote><p>a</p><ul><li>b</li></ul></blockquote></td> in XHTML, rendered as | a followed by an empty line and * b |.

Expected

A valid table, with the cell content kept on a single line (e.g. using <br/> or inline HTML).