Replace the kludge for the \z escape sequence by an actual

implementation.  As a side effect, minus ten lines of code.

As another side effect, this also fixes the assertion failure that
used to be triggered by "\z\o'ab'c" at the beginning of an output
line, found by jsg@ with afl (test case 022/Apr27).

1 files changed, 27 insertions, 43 deletions

diff --git a/term.c b/term.c
index 68f3ea04..79d116a3 100644
--- a/term.c
+++ b/term.c
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.247 2015/04/04 17:47:18 schwarze Exp $ */
+/*	$Id: term.c,v 1.248 2015/04/29 18:35:00 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -265,6 +265,7 @@ term_flushln(struct termp *p)
 
 	p->col = 0;
 	p->overstep = 0;
+	p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE);
 
 	if ( ! (TERMP_NOBREAK & p->flags)) {
 		p->viscol = 0;
@@ -417,11 +418,6 @@ term_word(struct termp *p, const char *word)
 
 	while ('\0' != *word) {
 		if ('\\' != *word) {
-			if (TERMP_SKIPCHAR & p->flags) {
-				p->flags &= ~TERMP_SKIPCHAR;
-				word++;
-				continue;
-			}
 			if (TERMP_NBRWORD & p->flags) {
 				if (' ' == *word) {
 					encode(p, nbrsp, 1);
@@ -480,13 +476,13 @@ term_word(struct termp *p, const char *word)
 			term_fontlast(p);
 			continue;
 		case ESCAPE_NOSPACE:
-			if (TERMP_SKIPCHAR & p->flags)
-				p->flags &= ~TERMP_SKIPCHAR;
-			else if ('\0' == *word)
+			if (p->flags & TERMP_BACKAFTER)
+				p->flags &= ~TERMP_BACKAFTER;
+			else if (*word == '\0')
 				p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
 			continue;
 		case ESCAPE_SKIPCHAR:
-			p->flags |= TERMP_SKIPCHAR;
+			p->flags |= TERMP_BACKAFTER;
 			continue;
 		case ESCAPE_OVERSTRIKE:
 			cp = seq + sz;
@@ -496,9 +492,14 @@ term_word(struct termp *p, const char *word)
 					continue;
 				}
 				encode1(p, *seq++);
-				if (seq < cp)
-					encode(p, "\b", 1);
+				if (seq < cp) {
+					if (p->flags & TERMP_BACKBEFORE)
+						p->flags |= TERMP_BACKAFTER;
+					else
+						p->flags |= TERMP_BACKBEFORE;
+				}
 			}
+			continue;
 		default:
 			continue;
 		}
@@ -553,16 +554,16 @@ encode1(struct termp *p, int c)
 {
 	enum termfont	  f;
 
-	if (TERMP_SKIPCHAR & p->flags) {
-		p->flags &= ~TERMP_SKIPCHAR;
-		return;
-	}
+	if (p->col + 7 >= p->maxcols)
+		adjbuf(p, p->col + 7);
 
-	if (p->col + 6 >= p->maxcols)
-		adjbuf(p, p->col + 6);
-
-	f = p->fontq[p->fonti];
+	f = (c == ASCII_HYPH || isgraph(c)) ?
+	    p->fontq[p->fonti] : TERMFONT_NONE;
 
+	if (p->flags & TERMP_BACKBEFORE) {
+		p->buf[p->col++] = 8;
+		p->flags &= ~TERMP_BACKBEFORE;
+	}
 	if (TERMFONT_UNDER == f || TERMFONT_BI == f) {
 		p->buf[p->col++] = '_';
 		p->buf[p->col++] = 8;
@@ -575,6 +576,10 @@ encode1(struct termp *p, int c)
 		p->buf[p->col++] = 8;
 	}
 	p->buf[p->col++] = c;
+	if (p->flags & TERMP_BACKAFTER) {
+		p->flags |= TERMP_BACKBEFORE;
+		p->flags &= ~TERMP_BACKAFTER;
+	}
 }
 
 static void
@@ -582,29 +587,8 @@ encode(struct termp *p, const char *word, size_t sz)
 {
 	size_t		  i;
 
-	if (TERMP_SKIPCHAR & p->flags) {
-		p->flags &= ~TERMP_SKIPCHAR;
-		return;
-	}
-
-	/*
-	 * Encode and buffer a string of characters.  If the current
-	 * font mode is unset, buffer directly, else encode then buffer
-	 * character by character.
-	 */
-
-	if (p->fontq[p->fonti] == TERMFONT_NONE) {
-		if (p->col + sz >= p->maxcols)
-			adjbuf(p, p->col + sz);
-		for (i = 0; i < sz; i++)
-			p->buf[p->col++] = word[i];
-		return;
-	}
-
-	/* Pre-buffer, assuming worst-case. */
-
-	if (p->col + 1 + (sz * 5) >= p->maxcols)
-		adjbuf(p, p->col + 1 + (sz * 5));
+	if (p->col + 2 + (sz * 5) >= p->maxcols)
+		adjbuf(p, p->col + 2 + (sz * 5));
 
 	for (i = 0; i < sz; i++) {
 		if (ASCII_HYPH == word[i] ||