As to the proposed patch, I'd like to hear the opinion of math users.
After some further investigation I found out that the bug was introduced
in changeset 10553: "Output \\ at the end of the last line if it is
empty (fixes bug 2067)". This is wrong, because outputting an extra "\\"
would mean that you really add an extra row. In the example of bug 2969,
this is visible because this extra line gets a number. In the first part
of the patch I reverted this change. I have no clue where bug 2067 is
about. Juergen, you can probably help me out here (it's your bug). At
least I can't seem to reproduce.
However, I think our current LaTeX output can be improved anyway. I think new
rows should always be started on a new line. I.e.,
\begin{align*}
a & = & b & = & c\\
\\
x & = & y & = & z\end{align*}
not
\begin{align*}
a & = & b & = & c\\
\\x & = & y & = & z\end{align*}
This is also corrected in the attached patch. Please note the explicit
comment added there: "append newline only if line wasn't completely
empty and this was not the last line in the grid". I always hate
reverting things that have such an explicit comment.
Is there a reason for not ouputting this:
\begin{align*}
a & = & b & = & c\\
\\
x & = & y & = & z
\end{align*}
?
Vincent
