Quotation and comma ordering

Hi,

I noticed a very strange rendering issue with single/double quotations and comma.

```markdown
“hello”, “hola”, 'what',
```

will be rendered as

```
“hello,” “hola,” ‘what,’
```

in the html and PDF. If I append an extra whitespace between `"` and `,`, the order will be respected.  Is this a bug in pandoc? I haven't seen this in LaTeX.