Comment 58 for bug 457791

(In reply to comment #50)
> (From update of attachment 414125 [details])
> I think you have at least two problems here, that I can see.
> One--configure.in is made up of M4 macros, which use square brackets [] as
> quoting characters. Thus, you can't use them in your program text as-is,
> they'll be removed. There is a function called 'changequote' that you can use
> to work around this. It's a little convoluted, but you can see an example in
> our configure.in in an mmap test, it's under the heading "See if mmap sees
> writes". (I'd link it, but I'm writing this on a plane.)

Mixing changequote and auto* represents a really bad idea in almost all cases. Automake provides a mechanism to write [ and ]:

http://www.gnu.org/software/automake/manual/autoconf/Quadrigraphs.html#Quadrigraphs