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, 10 insertions, 7 deletions

diff --git a/mdoc_man.c b/mdoc_man.c
index 6bf832e5..5af2bb04 100644
--- a/mdoc_man.c
+++ b/mdoc_man.c
@@ -29,8 +29,7 @@
 #include "mdoc.h"
 #include "main.h"
 
-#define	DECL_ARGS const struct mdoc_meta *meta, \
-		  const struct mdoc_node *n
+#define	DECL_ARGS const struct mdoc_meta *meta, struct mdoc_node *n
 
 struct	manact {
 	int		(*cond)(DECL_ARGS); /* DON'T run actions */
@@ -548,10 +547,10 @@ void
 man_mdoc(void *arg, const struct mdoc *mdoc)
 {
 	const struct mdoc_meta *meta;
-	const struct mdoc_node *n;
+	struct mdoc_node *n;
 
 	meta = mdoc_meta(mdoc);
-	n = mdoc_node(mdoc);
+	n = mdoc_node(mdoc)->child;
 
 	printf(".TH \"%s\" \"%s\" \"%s\" \"%s\" \"%s\"\n",
 	    meta->title,
@@ -567,15 +566,18 @@ man_mdoc(void *arg, const struct mdoc *mdoc)
 		fontqueue.head = fontqueue.tail = mandoc_malloc(8);
 		*fontqueue.tail = 'R';
 	}
-	print_node(meta, n);
+	while (n != NULL) {
+		print_node(meta, n);
+		n = n->next;
+	}
 	putchar('\n');
 }
 
 static void
 print_node(DECL_ARGS)
 {
-	const struct mdoc_node	*sub;
 	const struct manact	*act;
+	struct mdoc_node	*sub;
 	int			 cond, do_sub;
 
 	/*
@@ -588,6 +590,7 @@ print_node(DECL_ARGS)
 	act = NULL;
 	cond = 0;
 	do_sub = 1;
+	n->flags &= ~MDOC_ENDED;
 
 	if (MDOC_TEXT == n->type) {
 		/*
@@ -635,7 +638,7 @@ print_node(DECL_ARGS)
 		(*act->post)(meta, n);
 
 	if (ENDBODY_NOT != n->end)
-		n->pending->flags |= MDOC_ENDED;
+		n->body->flags |= MDOC_ENDED;
 
 	if (ENDBODY_NOSPACE == n->end)
 		outflags &= ~(MMAN_spc | MMAN_nl);