Delete the mdoc_node.pending pointer and the function calculating

it, make_pending(), which was the most difficult function of the
whole mdoc(7) parser.  After almost five years of maintaining this
hellhole, i just noticed the pointer isn't needed after all.

Blocks are always rewound in the reverse order they were opened;
that even holds for broken blocks.  Consequently, it is sufficient
to just mark broken blogs with the flag MDOC_BROKEN and breaking
blocks with the flag MDOC_ENDED.  When rewinding, instead of iterating
the pending pointers, just iterate from each broken block to its
parents, rewinding all that are MDOC_ENDED and stopping after
processing the first ancestor that it not MDOC_BROKEN.  For ENDBODY
markers, use the mdoc_node.body pointer in place of the former
mdoc_node.pending.

This also fixes an assertion failure found by jsg@ with afl,
test case #467 (Bo Bl It Bd Bc It), where (surprise surprise)
the pending pointer got corrupted.

Improved functionality, minus one function, minus one struct field,
minus 50 lines of code.

1 files changed, 4 insertions, 2 deletions

diff --git a/mdoc.c b/mdoc.c
index 8b589208..eb74df69 100644
--- a/mdoc.c
+++ b/mdoc.c
@@ -1,7 +1,7 @@
 /*	$Id$ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010, 2012-2015 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -419,8 +419,10 @@ mdoc_endbody_alloc(struct mdoc *mdoc, int line, int pos, enum mdoct tok,
 {
 	struct mdoc_node *p;
 
+	body->flags |= MDOC_ENDED;
+	body->parent->flags |= MDOC_ENDED;
 	p = node_alloc(mdoc, line, pos, tok, MDOC_BODY);
-	p->pending = body;
+	p->body = body;
 	p->norm = body->norm;
 	p->end = end;
 	node_append(mdoc, p);