On Thu, 19 Nov 2020 at 03:12, Stefan Kangas <stefan@marxist.se> wrote:

> rrt@sc3d.org writes:
>
> > A hash character does not always introduce a comment in autoconf code,
> > but autoconf-mode always colors if as if it did. Unfortunately, I
> > cannot really tell from the autoconf manual what the rules are. I
> > suspect that # does not start a comment if it is inside [...] quotes,
> > but I guess this should be checked.
>
> (This bug was reported 10 years ago, but unfortunately never got a reply
> at the time.)
>
> Could you give an example of some autoconf code where you believe the
> hash character is incorrectly identified as a comment?
>

A quick bit of grepping finds the in XEmacs's configure.ac. Note in
particular the contents of the first argument to AC_LANG_PROGRAM:

AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <features.h>],[
#if ! (defined __GLIBC__ || defined __GNU_LIBRARY__)
#error Not a GNU libc system :-(
******* ======= ******** &&&&&&&&
#endif
])], have_glibc=yes, have_glibc=no)

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