Restore the traditional behaviour of the man(7) single-font

macros .B, .I, .SM, and .SB that the next-line scope extends
to the end of the next logical input line and is not extended
if that line ends with a \c (no-space) escape sequence.

While improving a loosely related feature in the man(7) .TP
macro, a regression entered the groff codebase in groff
commit 3549fd9f (28-Apr-2017) caused by the usual sloppiness
of Bjarni Ingi Gislason.  Since that time, groff wrongly had \c
extend next-line scope to a second line for these macros.
In man.c rev. 1.127 (25-Aug-2018) i synched mandoc behaviour
with groff in this respect, unfortunately failing to notice
the recent regression in groff.  The groff regression was
finally fixed by gbranden@ in commit 09c028f3 (07-Jun-2022).

With the present commit, mandoc is back in sync with both GNU and
Heirloom roff regarding the interaction of single-font macros with \c.

diff --git a/usr.bin/mandoc/man.c b/usr.bin/mandoc/man.c
index 0a522b6..b719de7 100644 (file)
--- a/usr.bin/mandoc/man.c
+++ b/usr.bin/mandoc/man.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: man.c,v 1.136 2022/04/28 10:17:37 schwarze Exp $ */
+/* $OpenBSD: man.c,v 1.137 2022/08/16 22:59:48 schwarze Exp $ */
 /*
  * Copyright (c) 2013-2015,2017-2019,2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -74,16 +74,7 @@ man_hasc(char *start)
 void
 man_descope(struct roff_man *man, int line, int offs, char *start)
 {
-       /* Trailing \c keeps next-line scope open. */
-
-       if (start != NULL && man_hasc(start) != NULL)
-               return;
-
-       /*
-        * Co-ordinate what happens with having a next-line scope open:
-        * first close out the element scopes (if applicable),
-        * then close out the block scope (also if applicable).
-        */
+       /* First close out all next-line element scopes, if any. */
 
        if (man->flags & MAN_ELINE) {
                while (man->last->parent->type != ROFFT_ROOT &&
@@ -91,6 +82,14 @@ man_descope(struct roff_man *man, int line, int offs, char *start)
                        man_unscope(man, man->last->parent);
                man->flags &= ~MAN_ELINE;
        }
+
+       /* Trailing \c keeps next-line block scope open. */
+
+       if (start != NULL && man_hasc(start) != NULL)
+               return;
+
+       /* Close out the next-line block scope, if there is one. */
+
        if ( ! (man->flags & MAN_BLINE))
                return;
        man_unscope(man, man->last->parent);