bug#20301: 11.88.3; mathtools.el: multlined environment inserts a spurious newline

[gojjoe]

Dear All,

Inserting a multlined (note the final 'd') environment via 
LaTeX-environment, a spurious newline is inserted. Example: 
call C-c C-e multlined [ret]. The result is:

\begin{multlined}


\end{multlined}

with a spurious newline and the cursor in the second empty 
line. Insertion of all other math environments I tried 
behaves correctly instead, eg

\begin{equation}

\end{equation}

The same happens also inserting multlined when a region is 
selected. For example, marking the expression

a + b

(or its whole line) and calling C-c C-e multlined [ret] gives

\begin{multlined}
a + b

\end{multlined}

again with a spurious newline.

I think the problem is in mathtools.el: @line 198, maybe 
"newline-and-indent" is causing the problem?

Cheers!
J



Emacs  : GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601)
 of 2013-03-17 on MARVIN
Package: 11.88.3

current state:
==============
(setq
 AUCTeX-date "2015-03-22"
 window-system 'w32
 LaTeX-version "2e"
 TeX-style-path '("~/.emacs.d/auctex"
                  "c:/Users/***/work/.emacs.d/elpa/auctex-11.88.3/style"
                  "c:/Users/***/work/.emacs.d/auctex/auctex-auto"
                  "c:/Users/***/work/.emacs.d/auctex/auctex-style"
                  "auctex-auto" "auctex-style")
 TeX-auto-save t
 TeX-parse-self t
 TeX-master t
 )