Handle some predefined read-only number registers, e.g. .H and .V.

In particular, this improves handling of the pod2man(1) preamble;
for examples of the effect, see some author names in perlthrtut(1).

Missing feature reported by Andreas Voegele <mail at andreasvoegele dot com>
more than two years ago.  Written at Christchurch International Airport.

diff --git a/TODO b/TODO
index 26f42c23b4174286f797efdc2c8bf539bfd64ac6..afe950adc8afecb43672cfdaf75f2451cebcba98 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,6 +1,6 @@
 ************************************************************************
 * Official mandoc TODO.
-* $Id: TODO,v 1.162 2013/12/25 14:40:34 schwarze Exp $
+* $Id: TODO,v 1.163 2014/02/14 22:27:41 schwarze Exp $
 ************************************************************************
 
 ************************************************************************
@@ -15,11 +15,6 @@ None known.
 
 --- missing roff features ----------------------------------------------
 
-- roff.c should treat \n(.H>23 and \n(.V>19 in the pod2man(1)
-  preamble as true, see for example AUTHORS in MooseX::Getopt.3p
-  reported by Andreas Voegele <mail at andreasvoegele dot com>
-  Tue, 22 Nov 2011 15:34:47 +0100 on ports@
-
 - .ad (adjust margins)
   .ad l -- adjust left margin only (flush left)
   .ad r -- adjust right margin only (flush right)

diff --git a/roff.c b/roff.c
index ca8ab7bb6d8e04ea137d20651ba32bfc95a6d5b5..a3e34186c8d1ec54d754cd0fed5ea642779909fa 100644 (file)
--- a/roff.c
+++ b/roff.c
@@ -1,4 +1,4 @@
-/*     $Id: roff.c,v 1.191 2014/01/06 23:46:07 schwarze Exp $ */
+/*     $Id: roff.c,v 1.192 2014/02/14 22:27:41 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -192,6 +192,7 @@ static      int              roff_getnum(const char *, int *, int *);
 static int              roff_getop(const char *, int *, char *);
 static int              roff_getregn(const struct roff *,
                                const char *, size_t);
+static int              roff_getregro(const char *name);
 static const char      *roff_getstrn(const struct roff *, 
                                const char *, size_t);
 static enum rofferr     roff_it(ROFF_ARGS);
@@ -1380,10 +1381,45 @@ roff_setreg(struct roff *r, const char *name, int val, char sign)
                reg->val = val;
 }
 
+/*
+ * Handle some predefined read-only number registers.
+ * For now, return -1 if the requested register is not predefined;
+ * in case a predefined read-only register having the value -1
+ * were to turn up, another special value would have to be chosen.
+ */
+static int
+roff_getregro(const char *name)
+{
+
+       switch (*name) {
+       case ('A'):  /* ASCII approximation mode is always off. */
+               return(0);
+       case ('g'):  /* Groff compatibility mode is always on. */
+               return(1);
+       case ('H'):  /* Fixed horizontal resolution. */
+               return (24);
+       case ('j'):  /* Always adjust left margin only. */
+               return(0);
+       case ('T'):  /* Some output device is always defined. */
+               return(1);
+       case ('V'):  /* Fixed vertical resolution. */
+               return (40);
+       default:
+               return (-1);
+       }
+}
+
 int
 roff_getreg(const struct roff *r, const char *name)
 {
        struct roffreg  *reg;
+       int              val;
+
+       if ('.' == name[0] && '\0' != name[1] && '\0' == name[2]) {
+               val = roff_getregro(name + 1);
+               if (-1 != val)
+                       return (val);
+       }
 
        for (reg = r->regtab; reg; reg = reg->next)
                if (0 == strcmp(name, reg->key.p))
@@ -1396,6 +1432,13 @@ static int
 roff_getregn(const struct roff *r, const char *name, size_t len)
 {
        struct roffreg  *reg;
+       int              val;
+
+       if ('.' == name[0] && 2 == len) {
+               val = roff_getregro(name + 1);
+               if (-1 != val)
+                       return (val);
+       }
 
        for (reg = r->regtab; reg; reg = reg->next)
                if (len == reg->key.sz &&