===================================================================
RCS file: /cvs/mandoc/eqn_term.c,v
retrieving revision 1.7
retrieving revision 1.13
diff -u -p -r1.7 -r1.13
--- mandoc/eqn_term.c	2014/10/12 14:49:39	1.7
+++ mandoc/eqn_term.c	2017/07/08 14:51:04	1.13
@@ -1,7 +1,7 @@
-/*	$Id: eqn_term.c,v 1.7 2014/10/12 14:49:39 schwarze Exp $ */
+/*	$Id: eqn_term.c,v 1.13 2017/07/08 14:51:04 schwarze Exp $ */
 /*
  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2014 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2014, 2015, 2017 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
@@ -40,10 +40,10 @@ static void	eqn_box(struct termp *, const struct eqn_b
 
 
 void
-term_eqn(struct termp *p, const struct eqn *ep)
+term_eqn(struct termp *p, const struct eqn_box *bp)
 {
 
-	eqn_box(p, ep->root);
+	eqn_box(p, bp);
 	p->flags &= ~TERMP_NOSPACE;
 }
 
@@ -51,25 +51,46 @@ static void
 eqn_box(struct termp *p, const struct eqn_box *bp)
 {
 	const struct eqn_box *child;
+	int delim;
 
-	if (bp->type == EQN_LIST ||
+	/* Delimiters around this box? */
+
+	if ((bp->type == EQN_LIST && bp->expectargs > 1) ||
 	    (bp->type == EQN_PILE && (bp->prev || bp->next)) ||
-	    (bp->parent != NULL && bp->parent->pos == EQNPOS_SQRT)) {
+	    (bp->parent != NULL && (bp->parent->pos == EQNPOS_SQRT ||
+	    /* Diacritic followed by ^ or _. */
+	    ((bp->top != NULL || bp->bottom != NULL) &&
+	     bp->parent->type == EQN_SUBEXPR &&
+	     bp->parent->pos != EQNPOS_OVER && bp->next != NULL) ||
+	    /* Nested over, sub, sup, from, to. */
+	    (bp->type == EQN_SUBEXPR && bp->pos != EQNPOS_SQRT &&
+	     ((bp->parent->type == EQN_LIST && bp->expectargs == 1) ||
+	      (bp->parent->type == EQN_SUBEXPR &&
+	       bp->pos != EQNPOS_SQRT)))))) {
 		if (bp->parent->type == EQN_SUBEXPR && bp->prev != NULL)
 			p->flags |= TERMP_NOSPACE;
 		term_word(p, bp->left != NULL ? bp->left : "(");
 		p->flags |= TERMP_NOSPACE;
-	}
+		delim = 1;
+	} else
+		delim = 0;
+
+	/* Handle Fonts and text. */
+
 	if (bp->font != EQNFONT_NONE)
 		term_fontpush(p, fontmap[(int)bp->font]);
 
 	if (bp->text != NULL)
 		term_word(p, bp->text);
 
+	/* Special box types. */
+
 	if (bp->pos == EQNPOS_SQRT) {
 		term_word(p, "sqrt");
-		p->flags |= TERMP_NOSPACE;
-		eqn_box(p, bp->first);
+		if (bp->first != NULL) {
+			p->flags |= TERMP_NOSPACE;
+			eqn_box(p, bp->first);
+		}
 	} else if (bp->type == EQN_SUBEXPR) {
 		child = bp->first;
 		eqn_box(p, child);
@@ -79,40 +100,40 @@ eqn_box(struct termp *p, const struct eqn_box *bp)
 		     bp->pos == EQNPOS_TO) ? "^" : "_");
 		p->flags |= TERMP_NOSPACE;
 		child = child->next;
-		eqn_box(p, child);
-		if (bp->pos == EQNPOS_FROMTO ||
-		    bp->pos == EQNPOS_SUBSUP) {
-			p->flags |= TERMP_NOSPACE;
-			term_word(p, "^");
-			p->flags |= TERMP_NOSPACE;
-			child = child->next;
+		if (child != NULL) {
 			eqn_box(p, child);
+			if (bp->pos == EQNPOS_FROMTO ||
+			    bp->pos == EQNPOS_SUBSUP) {
+				p->flags |= TERMP_NOSPACE;
+				term_word(p, "^");
+				p->flags |= TERMP_NOSPACE;
+				child = child->next;
+				if (child != NULL)
+					eqn_box(p, child);
+			}
 		}
 	} else {
 		child = bp->first;
-		if (bp->type == EQN_MATRIX && child->type == EQN_LIST)
+		if (bp->type == EQN_MATRIX &&
+		    child != NULL &&
+		    child->type == EQN_LIST &&
+		    child->expectargs > 1)
 			child = child->first;
 		while (child != NULL) {
 			eqn_box(p,
 			    bp->type == EQN_PILE &&
 			    child->type == EQN_LIST &&
+			    child->expectargs > 1 &&
 			    child->args == 1 ?
 			    child->first : child);
 			child = child->next;
 		}
 	}
 
+	/* Handle Fonts and diacritics. */
+
 	if (bp->font != EQNFONT_NONE)
 		term_fontpop(p);
-	if (bp->type == EQN_LIST ||
-	    (bp->type == EQN_PILE && (bp->prev || bp->next)) ||
-	    (bp->parent != NULL && bp->parent->pos == EQNPOS_SQRT)) {
-		p->flags |= TERMP_NOSPACE;
-		term_word(p, bp->right != NULL ? bp->right : ")");
-		if (bp->parent->type == EQN_SUBEXPR && bp->next != NULL)
-			p->flags |= TERMP_NOSPACE;
-	}
-
 	if (bp->top != NULL) {
 		p->flags |= TERMP_NOSPACE;
 		term_word(p, bp->top);
@@ -120,5 +141,14 @@ eqn_box(struct termp *p, const struct eqn_box *bp)
 	if (bp->bottom != NULL) {
 		p->flags |= TERMP_NOSPACE;
 		term_word(p, "_");
+	}
+
+	/* Right delimiter after this box? */
+
+	if (delim) {
+		p->flags |= TERMP_NOSPACE;
+		term_word(p, bp->right != NULL ? bp->right : ")");
+		if (bp->parent->type == EQN_SUBEXPR && bp->next != NULL)
+			p->flags |= TERMP_NOSPACE;
 	}
 }