[Patch] [BZ 13761] Fix another unbound alloca

[Roland McGrath]

It's always easier to review when you include the patch afresh.
Off hand I see one typo (missing space before an =).
An XXX comment is not sufficient handling of malloc failure.
We need to figure out what is the robust behavior there.

Also, it's never really necessary to cast the result of malloc or alloca.
That's what void * is for (this is not C++).  There were gratuitous casts
in the old code, but there's no need to repeat the pattern.


Thanks,
Roland