AC_HELP_STRING eats quotes

[Roger Leigh]

I reported this on gnats, but I didn't know if it was still used, as
it's not mentioned in autoconf.info, only BUGS

The following macro has `[' and `]' characters within the quoted string.
However deeply I nest the quotes, they never appear in the output

AC_ARG_WITH(cups,
AC_HELP_STRING([--with-cups[=PREFIX]],
[build CUPS driver [default=${BUILD_CUPS}, default
+PREFIX=PREFIX]]),
...)

Output:
--with-cups=PREFIX build CUPS driver

The spacing is also foreshortened by the number of extra quotes it
removes. If I add extra quotes ad the ends of the strings, I get extra
commas between the words:

--with-cups=PREFIX
build, CUPS, driver, [default=${BUILD_CUPS},],[default], [PREFIX=PREFIX]

All I want to do here is have `[' and `]' in the help text. Using
changequote does not help: I get the following errors:

configure.ac:198: /usr/bin/m4: Bad expression in eval: m4_Cursor > 9
configure.ac:198: /usr/bin/m4: Bad expression in eval: m4_Cursor + 7 + 1
configure.ac:198: /usr/bin/m4: Bad expression in eval: > m4_Width 
configure.ac:198: error: m4_popdef: undefined: m4_Width
configure.ac:198: the top level

using 'changequote(<<, >>)...changequote([, ])'

Regards,
Roger

-- 
Roger Leigh ** Registration Number: 151826, http://counter.li.org **
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