When a conditional block is closed by putting "\}" on a text line

by itself (which is somewhat unusual but not invalid; most authors
use the empty macro line ".\}" instead), agree more closely with
groff and do not produce a double space in the output.

Quirk reported by millert@.

While here, tweak the rest of the function body of roff_cond_text()
to more closely match roff_cond_sub().  The subtly different handling
could make people (including myself) wonder whether there is any
point in being different.  Testing shows there is not.

4 files changed, 59 insertions, 11 deletions

diff --git a/regress/roff/cond/close.in b/regress/roff/cond/close.in
index 6bdf3781..74b402c8 100644
--- a/regress/roff/cond/close.in
+++ b/regress/roff/cond/close.in
@@ -1,5 +1,5 @@
 .\" $OpenBSD: close.in,v 1.3 2017/07/04 14:53:26 schwarze Exp $
-.TH COND-CLOSE 1 2013-06-27
+.TH COND-CLOSE 1 "November 26, 2018"
 .SH NAME
 cond-close \- closing conditional macros
 .SH DESCRIPTION
@@ -12,5 +12,21 @@ closing after an ignored macro
 .if t \{text \}
 closing after plain text
 .PP
+.if n \{conditional content \} following words with whitespace
+.PP
+.if n \{conditional content\}following words without whitespace
+.PP
+preceding words
+.if n \{\
+standard multi-line style
+.\}
+following words
+.PP
+preceding words
+.if n \{
+non-standard multi-line style
+\}
+following words
+.PP
 .if n \{
 still open at the end of the file
diff --git a/regress/roff/cond/close.out_ascii b/regress/roff/cond/close.out_ascii
index 244d4154..d049154d 100644
--- a/regress/roff/cond/close.out_ascii
+++ b/regress/roff/cond/close.out_ascii
@@ -12,8 +12,18 @@ DDEESSCCRRIIPPTTIIOONN
 
        closing after plain text
 
+       conditional content  following words with whitespace
+
+       conditional contentfollowing words without whitespace
+
+       preceding words standard multi-line style following words
+
+       preceding words
+
+       non-standard multi-line style following words
+
        still open at the end of the file
 
 
 
-OpenBSD                           2013-06-27                     COND-CLOSE(1)
+OpenBSD                        November 26, 2018                 COND-CLOSE(1)
diff --git a/regress/roff/cond/close.out_lint b/regress/roff/cond/close.out_lint
index 4387b057..d6f52146 100644
--- a/regress/roff/cond/close.out_lint
+++ b/regress/roff/cond/close.out_lint
@@ -1,2 +1,2 @@
-mandoc: close.in:15:2: ERROR: appending missing end of block: if
-mandoc: close.in:15:9: WARNING: skipping paragraph macro: sp after PP
+mandoc: close.in:31:2: ERROR: appending missing end of block: if
+mandoc: close.in:31:9: WARNING: skipping paragraph macro: sp after PP
diff --git a/roff.c b/roff.c
index deac9560..0fca8b9d 100644
--- a/roff.c
+++ b/roff.c
@@ -1,4 +1,4 @@
-/*	$Id: roff.c,v 1.342 2018/10/25 01:32:40 schwarze Exp $ */
+/*	$Id: roff.c,v 1.343 2018/11/26 17:44:34 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -2107,7 +2107,10 @@ roff_cond_sub(ROFF_ARGS)
 	if (ep[0] == '\\' && ep[1] == '}')
 		rr = 0;
 
-	/* Always check for the closing delimiter `\}'. */
+	/*
+	 * The closing delimiter `\}' rewinds the conditional scope
+	 * but is otherwise ignored when interpreting the line.
+	 */
 
 	while ((ep = strchr(ep, '\\')) != NULL) {
 		switch (ep[1]) {
@@ -2150,15 +2153,34 @@ roff_cond_text(ROFF_ARGS)
 	if (roffnode_cleanscope(r))
 		irc |= endloop;
 
+	/*
+	 * If `\}' occurs on a text line with neither preceding
+	 * nor following characters, drop the line completely.
+	 */
+
 	ep = buf->buf + pos;
+	if (strcmp(ep, "\\}") == 0)
+		rr = 0;
+
+	/*
+	 * The closing delimiter `\}' rewinds the conditional scope
+	 * but is otherwise ignored when interpreting the line.
+	 */
+
 	while ((ep = strchr(ep, '\\')) != NULL) {
-		if (*(++ep) == '}') {
-			*ep = '&';
-			if (roff_ccond(r, ln, ep - buf->buf - 1))
+		switch (ep[1]) {
+		case '}':
+			memmove(ep, ep + 2, strlen(ep + 2) + 1);
+			if (roff_ccond(r, ln, ep - buf->buf))
 				irc |= endloop;
-		}
-		if (*ep != '\0')
+			break;
+		case '\0':
 			++ep;
+			break;
+		default:
+			ep += 2;
+			break;
+		}
 	}
 	if (rr)
 		irc |= ROFF_CONT;