makeinfo build problem with security/heimdal (patch)

[Matthias Ferdinand <mf+ml.pkgsrc-users%netzwerkagentursaarland.de@localhost>]

Hello,

security/heimdal fails to build with modern texinfo (pkgsrc is at 5.2):

    ...
    Making all in doc
    sed -e 's,[@]dbdir[@],/var/heimdal,g'  -e 's,[@]PACKAGE_VERSION[@],1.5.3,g' < ./vars.tin > vars.texi.tmp
    chmod +x vars.texi.tmp
    mv vars.texi.tmp vars.texi
    restore=: && backupdir=".am$$" &&  am__cwd=`pwd` && CDPATH="${ZSH_VERSION+.}:" && cd . &&  rm -rf $backupdir && mkdir $backupdir &&  if (/opt/pkgsrc/work/pkgsrc/security/heimdal/default/.tools/bin/makeinfo --version) >/dev/null 2>&1; then  for f in ./heimdal.info ./heimdal.info-[0-9] ./heimdal.info-[0-9][0-9] ./heimdal.i[0-9] ./heimdal.i[0-9][0-9]; do  if test -f $f; then mv $f $backupdir; restore=mv; else :; fi;  done;  else :; fi &&  cd "$am__cwd";  if /opt/pkgsrc/work/pkgsrc/security/heimdal/default/.tools/bin/makeinfo  --css-include=./heimdal.css -I .  -o ./heimdal.info ./heimdal.texi;  then  rc=0;  CDPATH="${ZSH_VERSION+.}:" && cd .;  else  rc=$?;  CDPATH="${ZSH_VERSION+.}:" && cd . &&  $restore $backupdir/* `echo "././heimdal.info" | sed 's|[^/]*$||'`;  fi;  rm -rf $backupdir; exit $rc
=>  ./whatis.texi:39: unknown command `def'
    ./whatis.texi:39: unknown command `xsub'
    ./whatis.texi:40: unknown command `global'
    ./whatis.texi:40: unknown command `let'
    ./whatis.texi:40: unknown command `xsub' (possibly involving @sub)
    ./win2k.texi:314: warning: @end should only appear at a line beginning
    *** Error code 1



the attached patch fixes the build error for texinfo 5.2 and still
works with texinfo 4.11. But my tex / makeinfo skills are not sufficient
to tell if the changed version is functionally the same.

Regards
Matthias

$NetBSD$

--- doc/whatis.texi.orig	2012-12-09 22:06:44.000000000 +0000
+++ doc/whatis.texi
@@ -35,10 +35,10 @@ services can authenticate each other.
 @end macro
 @end ifinfo
 
-@tex
+@iftex
 @def@xsub#1{$_{#1}$}
 @global@let@sub=@xsub
-@end tex
+@end iftex
 
 @ifhtml
 @macro sub{arg}