(check-texinfo): Add a check to ensure future

consistency in using @sc{nul}, not `NUL'.

diff --git a/doc/Makefile.am b/doc/Makefile.am
index a870d1e..ad8e92b 100644 (file)
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -25,10 +25,13 @@ $(DVIS): $(EXTRA_DIST)
 $(INFO_DEPS): $(EXTRA_DIST)
 
 # List words/regexps here that should not appear in the texinfo documentation.
+# E.g., use @sc{nul}, not `NUL'
+# and use `time zone', not `timezone'.
 check-texinfo:
        fail=0; \
        grep timezone $(srcdir)/*.texi && fail=1; \
        grep non-zero $(srcdir)/*.texi && fail=1; \
+       grep -w NUL $(srcdir)/*.texi && fail=1; \
        grep '\$$@"' $(srcdir)/*.texi && fail=1; \
        $(PERL) -e 1 2> /dev/null && { $(PERL) -ne \
          '/\bPOSIX\b/ && !/\@acronym{POSIX}/ && !/^\* / || /{posix}/ and print,exit 1' \