mandoc: Do not die on an assertion if an input file contains no section

mandoc: Do not die on an assertion if an input file contains no section

[schwarze]

Log Message:
-----------
Do not die on an assertion if an input file contains no section
whatsoever and ends with a broken next-line scope.  Obviously, this
cannot happen in a real manual page, but mandoc(1) should not die
even when fed absurd input.

This bug was independently reported by both jsg@ and tb@ who both
found it with afl(1).

Modified Files:
--------------
    mandoc:
        man_macro.c
    mandoc/regress/man/TH:
        nobody.in
        nobody.out_ascii
        nobody.out_lint

Revision Data
-------------
Index: man_macro.c
===================================================================
RCS file: /home/cvs/mandoc/mandoc/man_macro.c,v
retrieving revision 1.145
retrieving revision 1.146
diff -Lman_macro.c -Lman_macro.c -u -p -r1.145 -r1.146
--- man_macro.c
+++ man_macro.c
@@ -1,7 +1,7 @@
 /* $Id$ */
 /*
+ * Copyright (c) 2012-2015,2017-2020,2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2012-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2013 Franco Fichtner <franco@lastsummer.de>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -108,7 +108,8 @@ man_unscope(struct roff_man *man, const 
 				    n->line, n->pos,
 				    "EOF breaks %s", roff_name[n->tok]);
 				if (man->flags & MAN_ELINE) {
-					if ((man_macro(n->parent->tok)->flags &
+					if (n->parent->type == ROFFT_ROOT ||
+					    (man_macro(n->parent->tok)->flags &
 					    MAN_ESCOPED) == 0)
 						man->flags &= ~MAN_ELINE;
 				} else {
Index: nobody.in
===================================================================
RCS file: /home/cvs/mandoc/mandoc/regress/man/TH/nobody.in,v
retrieving revision 1.2
retrieving revision 1.3
diff -Lregress/man/TH/nobody.in -Lregress/man/TH/nobody.in -u -p -r1.2 -r1.3
--- regress/man/TH/nobody.in
+++ regress/man/TH/nobody.in
@@ -1,2 +1,3 @@
-.\" $OpenBSD: nobody.in,v 1.2 2017/07/04 14:53:24 schwarze Exp $
-.TH TH-NOBODY 1 "June 20, 2014"
+.\" $OpenBSD: nobody.in,v 1.3 2022/04/13 14:37:34 schwarze Exp $
+.TH TH-NOBODY 1 "April 13, 2022"
+.B
Index: nobody.out_lint
===================================================================
RCS file: /home/cvs/mandoc/mandoc/regress/man/TH/nobody.out_lint,v
retrieving revision 1.4
retrieving revision 1.5
diff -Lregress/man/TH/nobody.out_lint -Lregress/man/TH/nobody.out_lint -u -p -r1.4 -r1.5
--- regress/man/TH/nobody.out_lint
+++ regress/man/TH/nobody.out_lint
@@ -1 +1,2 @@
+mandoc: nobody.in:3:2: WARNING: line scope broken: EOF breaks B
 mandoc: nobody.in: WARNING: no document body
Index: nobody.out_ascii
===================================================================
RCS file: /home/cvs/mandoc/mandoc/regress/man/TH/nobody.out_ascii,v
retrieving revision 1.2
retrieving revision 1.3
diff -Lregress/man/TH/nobody.out_ascii -Lregress/man/TH/nobody.out_ascii -u -p -r1.2 -r1.3
--- regress/man/TH/nobody.out_ascii
+++ regress/man/TH/nobody.out_ascii
@@ -1,3 +1,3 @@
 TH-NOBODY(1)                General Commands Manual               TH-NOBODY(1)
 
-OpenBSD                          June 20, 2014                    TH-NOBODY(1)
+OpenBSD                         April 13, 2022                    TH-NOBODY(1)
--
 To unsubscribe send an email to source+unsubscribe@mandoc.bsd.lv