===================================================================
RCS file: /cvs/mandoc/tag.c,v
retrieving revision 1.15
retrieving revision 1.16
diff -u -p -r1.15 -r1.16
--- mandoc/tag.c	2016/11/08 15:57:28	1.15
+++ mandoc/tag.c	2016/11/08 16:23:58	1.16
@@ -1,4 +1,4 @@
-/*	$Id: tag.c,v 1.15 2016/11/08 15:57:28 schwarze Exp $ */
+/*	$Id: tag.c,v 1.16 2016/11/08 16:23:58 schwarze Exp $ */
 /*
  * Copyright (c) 2015, 2016 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -155,14 +155,22 @@ tag_put(const char *s, int prio, size_t line)
 
 	} else {
 
+		/* Handle priority 0 entries. */
+
+		if (prio == 0) {
+			if (entry->prio == 0)
+				entry->prio = -1;
+			return;
+		}
+
 		/* A better entry is already present, ignore the new one. */
 
-		if (entry->prio < prio)
+		if (entry->prio > 0 && entry->prio < prio)
 			return;
 
 		/* The existing entry is worse, clear it. */
 
-		if (entry->prio > prio)
+		if (entry->prio < 1 || entry->prio > prio)
 			entry->nlines = 0;
 	}
 
@@ -194,7 +202,7 @@ tag_write(void)
 	stream = fdopen(tag_files.tfd, "w");
 	entry = ohash_first(&tag_data, &slot);
 	while (entry != NULL) {
-		if (stream != NULL)
+		if (stream != NULL && entry->prio >= 0)
 			for (i = 0; i < entry->nlines; i++)
 				fprintf(stream, "%s %s %zu\n",
 				    entry->s, tag_files.ofn, entry->lines[i]);