doc strerror_r

[Kevin Ryde]

        * doc/autoconf.texi (Function Portability): Add strerror_r, cross
        referencing AC_FUNC_STRERROR_R.

--- autoconf.texi.~1.806.~      2004-03-25 08:35:26.000000000 +1000
+++ autoconf.texi       2004-03-25 09:02:35.000000000 +1000
@@ -3714,6 +3714,14 @@
 Porting the @acronym{GNU} Compiler Collection}).  Apparently in some cases even
 having format strings read-only can be a problem.
 
address@hidden @code{strerror_r}
address@hidden @fuindex strerror_r
address@hidden @code{strerror_r}
+POSIX specifies @code{strerror_r} returning an @code{int}, but glibc
+provides a different version returning a @code{char *}.
address@hidden can detect which is available
+(@pxref{Particular Functions}).
+
 @item @code{strnlen}
 @c @fuindex strnlen
 @prindex @code{strnlen}