Multline environment becomes array environment

Steps to reproduce:
In user preference, turn on Export mathemaical formulas as MathJax
Type \multline* to create a multline environment

In the menu, click Edit » Copy to html
The result is

  \(\displaystyle \begin{array}{l}
  \sum_{k = 0}^{\infty} (\alpha + k)
  (\alpha + k - 1) a_k x^{\alpha + k} -
  \sum_{k = 0}^{\infty} (\alpha + k)
  (\alpha + k - 1) a_k x^{\alpha + k - 1}\\
  + \sum_{k = 0}^{\infty} 3
  (\alpha + k) a_k x^{\alpha + k} + \sum_{k =
  0}^{\infty} a_k x^{\alpha + k}
  = 0

multline environment becomes array environment, so the second line is left-aligned (but should be right-aligned).

To me it seems like a bug (to be reported on the bug tracker at Savannah, .
Let us see what someone else says.