Support for badly nested blocks, written around the time of

the Rostock mandoc hackathon and tested and polished since,
supporting constructs like:

.Ao Bo    Ac    Bc        (exp breaking exp)
.Aq Bo    eol   Bc        (imp breaking exp)
.Ao Bq    Ac    eol       (exp breaking imp)
.Ao Bo So Bc    Ac  Sc    (double break, inner before outer)
.Ao Bo So Ac    Bc  Sc    (double break, outer before inner)
.Ao Bo    Ac So Bc  Sc    (broken breaker)
.Ao Bo So Bc Do Ac  Sc Dc (broken double breaker)

There are still two known issues which are tricky:

1) Breaking two identical explicit blocks (Ao Bo Bo Ac or Aq Bo Bo eol)
fails outright, triggering a bogus syntax error.
2) Breaking a block by two identical explicit blocks (Ao Ao Bo Ac Ac Bc
or Ao Ao Bq Ac Ac eol) still has a minor rendering error left:
"<ao1 <ao2 [bo ac2> ac1> bc]>" should not have the final ">".

We can fix these later in the tree, let's not grow this diff too large.

"get it in" kristaps@

1 files changed, 8 insertions, 0 deletions

diff --git a/mdoc.h b/mdoc.h
index e09256f1..06b09270 100644
--- a/mdoc.h
+++ b/mdoc.h
@@ -249,6 +249,12 @@ struct 	mdoc_arg {
 	unsigned int	  refcnt;
 };
 
+enum	mdoc_endbody {
+	ENDBODY_NOT = 0,
+	ENDBODY_SPACE,
+	ENDBODY_NOSPACE,
+};
+
 enum	mdoc_list {
 	LIST__NONE = 0,
 	LIST_bullet,
@@ -302,6 +308,7 @@ struct	mdoc_node {
 #define	MDOC_EOS	 (1 << 2) /* at sentence boundary */
 #define	MDOC_LINE	 (1 << 3) /* first macro/text on line */
 #define	MDOC_SYNPRETTY	 (1 << 4) /* SYNOPSIS-style formatting */
+#define	MDOC_ENDED	 (1 << 5) /* rendering has been ended */
 	enum mdoc_type	  type; /* AST node type */
 	enum mdoc_sec	  sec; /* current named section */
 	/* FIXME: these can be union'd to shave a few bytes. */
@@ -311,6 +318,7 @@ struct	mdoc_node {
 	struct mdoc_node *body;		/* BLOCK */
 	struct mdoc_node *tail;		/* BLOCK */
 	char		 *string;	/* TEXT */
+	enum mdoc_endbody end;		/* BODY */
 
 	union {
 		struct mdoc_bl Bl;