11989.md

A `w:gridCol` need not have a width (`w:w`). Such a column is kept,
and since its width is missing, every column gets the default width.

```
% pandoc command/11989.docx -t html
^D
<table>
<tbody>
<tr>
<td>a</td>
<td>b</td>
</tr>
<tr>
<td>c</td>
<td>d</td>
</tr>
</tbody>
</table>
```