===================================================================
RCS file: /cvs/mandoc/term.c,v
retrieving revision 1.89
retrieving revision 1.98
diff -u -p -r1.89 -r1.98
--- mandoc/term.c	2009/07/16 13:17:51	1.89
+++ mandoc/term.c	2009/09/15 08:16:20	1.98
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.89 2009/07/16 13:17:51 kristaps Exp $ */
+/*	$Id: term.c,v 1.98 2009/09/15 08:16:20 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -31,13 +31,16 @@ extern	int		  mdoc_run(struct termp *, 
 
 static	struct termp	 *term_alloc(enum termenc);
 static	void		  term_free(struct termp *);
-static	void		  term_pescape(struct termp *, const char **);
-static	void		  term_nescape(struct termp *,
+
+static	void		  do_escaped(struct termp *, const char **);
+static	void		  do_special(struct termp *,
 				const char *, size_t);
-static	void		  term_chara(struct termp *, char);
-static	void		  term_encodea(struct termp *, char);
-static	int		  term_isopendelim(const char *);
-static	int		  term_isclosedelim(const char *);
+static	void		  do_reserved(struct termp *,
+				const char *, size_t);
+static	void		  buffer(struct termp *, char);
+static	void		  encode(struct termp *, char);
+static	int		  isopendelim(const char *);
+static	int		  isclosedelim(const char *);
 
 
 void *
@@ -101,7 +104,7 @@ term_alloc(enum termenc enc)
 	struct termp *p;
 
 	if (NULL == (p = malloc(sizeof(struct termp))))
-		err(1, "malloc");
+		return(NULL);
 	bzero(p, sizeof(struct termp));
 	p->maxrmargin = 78;
 	p->enc = enc;
@@ -110,7 +113,7 @@ term_alloc(enum termenc enc)
 
 
 static int
-term_isclosedelim(const char *p)
+isclosedelim(const char *p)
 {
 
 	if ( ! (*p && 0 == *(p + 1)))
@@ -144,7 +147,7 @@ term_isclosedelim(const char *p)
 
 
 static int
-term_isopendelim(const char *p)
+isopendelim(const char *p)
 {
 
 	if ( ! (*p && 0 == *(p + 1)))
@@ -184,6 +187,9 @@ term_isopendelim(const char *p)
  *    columns.  In short: don't print a newline and instead pad to the
  *    right margin.  Used in conjunction with TERMP_NOLPAD.
  *
+ *  - TERMP_TWOSPACE: when padding, make sure there are at least two
+ *    space characters of padding.  Otherwise, rather break the line.
+ *
  *  - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
  *    the line is overrun, and don't pad-right if it's underrun.
  *
@@ -202,16 +208,13 @@ term_isopendelim(const char *p)
  *  Otherwise, the line will break at the right margin.  Extremely long
  *  lines will cause the system to emit a warning (TODO: hyphenate, if
  *  possible).
- *
- *  FIXME: newline breaks occur (in groff) also occur when a single
- *  space follows a NOBREAK!
  */
 void
 term_flushln(struct termp *p)
 {
 	int		 i, j;
 	size_t		 vbl, vsz, vis, maxvis, mmax, bp;
-	static int	 sv = -1;
+	static int	 overstep = 0;
 
 	/*
 	 * First, establish the maximum columns of "visible" content.
@@ -221,16 +224,17 @@ term_flushln(struct termp *p)
 	 */
 
 	assert(p->offset < p->rmargin);
-	maxvis = p->rmargin - p->offset;
-	mmax = p->maxrmargin - p->offset;
+	assert((int)(p->rmargin - p->offset) - overstep > 0);
+
+	maxvis = /* LINTED */
+		p->rmargin - p->offset - overstep;
+	mmax = /* LINTED */
+		p->maxrmargin - p->offset - overstep;
+
 	bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
 	vis = 0;
+	overstep = 0;
 
-	if (sv >= 0) {
-		vis = (size_t)sv;
-		sv = -1;
-	}
-
 	/*
 	 * If in the standard case (left-justified), then begin with our
 	 * indentation, otherwise (columns, etc.) just start spitting
@@ -252,7 +256,7 @@ term_flushln(struct termp *p)
 
 		/* LINTED */
 		for (j = i, vsz = 0; j < (int)p->col; j++) {
-			if (' ' == p->buf[j]) 
+			if (j && ' ' == p->buf[j]) 
 				break;
 			else if (8 == p->buf[j])
 				vsz--;
@@ -299,38 +303,48 @@ term_flushln(struct termp *p)
 		}
 		vis += vsz;
 	}
+	p->col = 0;
 
-	/*
-	 * If we've overstepped our maximum visible no-break space, then
-	 * cause a newline and offset at the right margin.
-	 */
-
-	if ((TERMP_NOBREAK & p->flags) && vis >= maxvis) {
-		if ( ! (TERMP_DANGLE & p->flags) &&
-				! (TERMP_HANG & p->flags)) {
-			putchar('\n');
-			for (i = 0; i < (int)p->rmargin; i++)
-				putchar(' ');
-		}
-		if (TERMP_HANG & p->flags)
-			sv = (int)(vis - maxvis);
-		p->col = 0;
+	if ( ! (TERMP_NOBREAK & p->flags)) {
+		putchar('\n');
 		return;
 	}
 
-	/*
-	 * If we're not to right-marginalise it (newline), then instead
-	 * pad to the right margin and stay off.
-	 */
+	if (TERMP_HANG & p->flags) {
+		/* We need one blank after the tag. */
+		overstep = /* LINTED */
+			vis - maxvis + 1;
 
-	if (p->flags & TERMP_NOBREAK) {
-		if ( ! (TERMP_DANGLE & p->flags))
-			for ( ; vis < maxvis; vis++)
-				putchar(' ');
-	} else
-		putchar('\n');
+		/*
+		 * Behave exactly the same way as groff:
+		 * If we have overstepped the margin, temporarily move
+		 * it to the right and flag the rest of the line to be
+		 * shorter.
+		 * If we landed right at the margin, be happy.
+		 * If we are one step before the margin, temporarily
+		 * move it one step LEFT and flag the rest of the line
+		 * to be longer.
+		 */
+		if (overstep >= -1) {
+			assert((int)maxvis + overstep >= 0);
+			/* LINTED */
+			maxvis += overstep;
+		} else
+			overstep = 0;
 
-	p->col = 0;
+	} else if (TERMP_DANGLE & p->flags)
+		return;
+
+	/* Right-pad. */
+	if (maxvis > vis + /* LINTED */
+			((TERMP_TWOSPACE & p->flags) ? 1 : 0))  
+		for ( ; vis < maxvis; vis++)
+			putchar(' ');
+	else {	/* ...or newline break. */
+		putchar('\n');
+		for (i = 0; i < (int)p->rmargin; i++)
+			putchar(' ');
+	}
 }
 
 
@@ -368,13 +382,8 @@ term_vspace(struct termp *p)
 }
 
 
-/*
- * Determine the symbol indicated by an escape sequences, that is, one
- * starting with a backslash.  Once done, we pass this value into the
- * output buffer by way of the symbol table.
- */
 static void
-term_nescape(struct termp *p, const char *word, size_t len)
+do_special(struct termp *p, const char *word, size_t len)
 {
 	const char	*rhs;
 	size_t		 sz;
@@ -382,24 +391,56 @@ term_nescape(struct termp *p, const char *word, size_t
 
 	rhs = term_a2ascii(p->symtab, word, len, &sz);
 
-	if (rhs)
-		for (i = 0; i < (int)sz; i++) 
-			term_encodea(p, rhs[i]);
+	if (NULL == rhs) {
+#if 0
+		fputs("Unknown special character: ", stderr);
+		for (i = 0; i < (int)len; i++)
+			fputc(word[i], stderr);
+		fputc('\n', stderr);
+#endif
+		return;
+	}
+	for (i = 0; i < (int)sz; i++) 
+		encode(p, rhs[i]);
 }
 
 
+static void
+do_reserved(struct termp *p, const char *word, size_t len)
+{
+	const char	*rhs;
+	size_t		 sz;
+	int		 i;
+
+	rhs = term_a2res(p->symtab, word, len, &sz);
+
+	if (NULL == rhs) {
+#if 0
+		fputs("Unknown reserved word: ", stderr);
+		for (i = 0; i < (int)len; i++)
+			fputc(word[i], stderr);
+		fputc('\n', stderr);
+#endif
+		return;
+	}
+	for (i = 0; i < (int)sz; i++) 
+		encode(p, rhs[i]);
+}
+
+
 /*
  * Handle an escape sequence: determine its length and pass it to the
  * escape-symbol look table.  Note that we assume mdoc(3) has validated
  * the escape sequence (we assert upon badly-formed escape sequences).
  */
 static void
-term_pescape(struct termp *p, const char **word)
+do_escaped(struct termp *p, const char **word)
 {
-	int		 j;
+	int		 j, type;
 	const char	*wp;
 
 	wp = *word;
+	type = 1;
 
 	if (0 == *(++wp)) {
 		*word = wp;
@@ -413,7 +454,7 @@ term_pescape(struct termp *p, const char **word)
 			return;
 		}
 
-		term_nescape(p, wp, 2);
+		do_special(p, wp, 2);
 		*word = ++wp;
 		return;
 
@@ -431,13 +472,14 @@ term_pescape(struct termp *p, const char **word)
 				return;
 			}
 
-			term_nescape(p, wp, 2);
+			do_reserved(p, wp, 2);
 			*word = ++wp;
 			return;
 		case ('['):
+			type = 0;
 			break;
 		default:
-			term_nescape(p, wp, 1);
+			do_reserved(p, wp, 1);
 			*word = wp;
 			return;
 		}
@@ -450,15 +492,15 @@ term_pescape(struct termp *p, const char **word)
 
 		switch (*wp) {
 		case ('B'):
-			p->flags |= TERMP_BOLD;
+			p->bold++;
 			break;
 		case ('I'):
-			p->flags |= TERMP_UNDER;
+			p->under++;
 			break;
 		case ('P'):
 			/* FALLTHROUGH */
 		case ('R'):
-			p->flags &= ~TERMP_STYLE;
+			p->bold = p->under = 0;
 			break;
 		default:
 			break;
@@ -468,7 +510,7 @@ term_pescape(struct termp *p, const char **word)
 		return;
 
 	} else if ('[' != *wp) {
-		term_nescape(p, wp, 1);
+		do_special(p, wp, 1);
 		*word = wp;
 		return;
 	}
@@ -482,7 +524,10 @@ term_pescape(struct termp *p, const char **word)
 		return;
 	}
 
-	term_nescape(p, wp - j, (size_t)j);
+	if (type)
+		do_special(p, wp - j, (size_t)j);
+	else
+		do_reserved(p, wp - j, (size_t)j);
 	*word = wp;
 }
 
@@ -497,28 +542,23 @@ term_word(struct termp *p, const char *word)
 {
 	const char	 *sv;
 
-	if (term_isclosedelim(word))
+	if (isclosedelim(word))
 		if ( ! (TERMP_IGNDELIM & p->flags))
 			p->flags |= TERMP_NOSPACE;
 
 	if ( ! (TERMP_NOSPACE & p->flags))
-		term_chara(p, ' ');
+		buffer(p, ' ');
 
 	if ( ! (p->flags & TERMP_NONOSPACE))
 		p->flags &= ~TERMP_NOSPACE;
 
-	/* 
-	 * If ANSI (word-length styling), then apply our style now,
-	 * before the word.
-	 */
-
 	for (sv = word; *word; word++)
 		if ('\\' != *word)
-			term_encodea(p, *word);
+			encode(p, *word);
 		else
-			term_pescape(p, &word);
+			do_escaped(p, &word);
 
-	if (term_isopendelim(sv))
+	if (isopendelim(sv))
 		p->flags |= TERMP_NOSPACE;
 }
 
@@ -529,7 +569,7 @@ term_word(struct termp *p, const char *word)
  * size.
  */
 static void
-term_chara(struct termp *p, char c)
+buffer(struct termp *p, char c)
 {
 	size_t		 s;
 
@@ -539,7 +579,7 @@ term_chara(struct termp *p, char c)
 		s = p->maxcols * 2;
 		p->buf = realloc(p->buf, s);
 		if (NULL == p->buf)
-			err(1, "realloc");
+			err(1, "realloc"); /* FIXME: shouldn't be here! */
 		p->maxcols = s;
 	}
 	p->buf[(int)(p->col)++] = c;
@@ -547,18 +587,18 @@ term_chara(struct termp *p, char c)
 
 
 static void
-term_encodea(struct termp *p, char c)
+encode(struct termp *p, char c)
 {
 	
-	if (' ' != c && TERMP_STYLE & p->flags) {
-		if (TERMP_BOLD & p->flags) {
-			term_chara(p, c);
-			term_chara(p, 8);
+	if (' ' != c) {
+		if (p->bold) {
+			buffer(p, c);
+			buffer(p, 8);
 		}
-		if (TERMP_UNDER & p->flags) {
-			term_chara(p, '_');
-			term_chara(p, 8);
+		if (p->under) {
+			buffer(p, '_');
+			buffer(p, 8);
 		}
 	}
-	term_chara(p, c);
+	buffer(p, c);
 }