From: schwarze <schwarze@openbsd.org>
Date: Mon, 10 Jan 2022 17:59:45 +0000 (+0000)
Subject: When rendering the \h (horizontal motion) low-level roff(7) escape
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=6c5a416ab58043071f7a44a23338e6118ccc1ed9;p=openbsd

When rendering the \h (horizontal motion) low-level roff(7) escape
sequence in -T ps and -T pdf output mode, use an appropriate
horizontal distance by correctly using the term_len() utility
function.  Output from the -T ascii, -T utf8, and -T html modes
was already correct and remains unchanged.

Lennart Jablonka <hummsmith42 at gmail dot com> found and reported
this unit conversion bug (misinterpreting AFM units as if they were
en units) when rendering scdoc-generated manuals (which is a low
quality generator, but that's no excuse for mandoc misformatting \h)
on Alpine Linux.  Lennart also tested this patch.
---

diff --git a/usr.bin/mandoc/term.c b/usr.bin/mandoc/term.c
index 2be4eb4aec9..9cc69aa9056 100644
--- a/usr.bin/mandoc/term.c
+++ b/usr.bin/mandoc/term.c
@@ -1,6 +1,6 @@
-/* $OpenBSD: term.c,v 1.144 2021/10/04 18:56:24 schwarze Exp $ */
+/* $OpenBSD: term.c,v 1.145 2022/01/10 17:59:45 schwarze Exp $ */
 /*
- * Copyright (c) 2010-2021 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010-2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -634,12 +634,14 @@ term_word(struct termp *p, const char *word)
 			if (a2roffsu(seq, &su, SCALE_EM) == NULL)
 				continue;
 			uc += term_hen(p, &su);
-			if (uc > 0)
-				while (uc-- > 0)
+			if (uc > 0) {
+				while (uc > 0) {
 					bufferc(p, ASCII_NBRSP);
-			else if (p->col > (size_t)(-uc))
+					uc -= term_len(p, 1);
+				}
+			} else if (p->col > (size_t)(-uc)) {
 				p->col += uc;
-			else {
+			} else {
 				uc += p->col;
 				p->col = 0;
 				if (p->tcol->offset > (size_t)(-uc)) {