===================================================================
RCS file: /cvs/mandoc/tag.c,v
retrieving revision 1.19
retrieving revision 1.25
diff -u -p -r1.19 -r1.25
--- mandoc/tag.c	2018/02/23 16:47:10	1.19
+++ mandoc/tag.c	2019/07/27 13:40:57	1.25
@@ -1,6 +1,6 @@
-/*	$Id: tag.c,v 1.19 2018/02/23 16:47:10 schwarze Exp $ */
+/*	$Id: tag.c,v 1.25 2019/07/27 13:40:57 schwarze Exp $ */
 /*
- * Copyright (c) 2015, 2016 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2015, 2016, 2018, 2019 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
@@ -18,6 +18,8 @@
 
 #include <sys/types.h>
 
+#include <errno.h>
+#include <limits.h>
 #include <signal.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -28,6 +30,7 @@
 
 #include "mandoc_aux.h"
 #include "mandoc_ohash.h"
+#include "mandoc.h"
 #include "tag.h"
 
 struct tag_entry {
@@ -50,7 +53,7 @@ static struct tag_files	 tag_files;
  * but for simplicity, create it anyway.
  */
 struct tag_files *
-tag_init(void)
+tag_init(char *tagname)
 {
 	struct sigaction	 sa;
 	int			 ofd;
@@ -58,6 +61,7 @@ tag_init(void)
 	ofd = -1;
 	tag_files.tfd = -1;
 	tag_files.tcpgid = -1;
+	tag_files.tagname = tagname;
 
 	/* Clean up when dying from a signal. */
 
@@ -79,8 +83,10 @@ tag_init(void)
 
 	/* Save the original standard output for use by the pager. */
 
-	if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1)
+	if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1) {
+		mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
 		goto fail;
+	}
 
 	/* Create both temporary output files. */
 
@@ -88,12 +94,20 @@ tag_init(void)
 	    sizeof(tag_files.ofn));
 	(void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
 	    sizeof(tag_files.tfn));
-	if ((ofd = mkstemp(tag_files.ofn)) == -1)
+	if ((ofd = mkstemp(tag_files.ofn)) == -1) {
+		mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
+		    "%s: %s", tag_files.ofn, strerror(errno));
 		goto fail;
-	if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1)
+	}
+	if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1) {
+		mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
+		    "%s: %s", tag_files.tfn, strerror(errno));
 		goto fail;
-	if (dup2(ofd, STDOUT_FILENO) == -1)
+	}
+	if (dup2(ofd, STDOUT_FILENO) == -1) {
+		mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
 		goto fail;
+	}
 	close(ofd);
 
 	/*
@@ -116,46 +130,63 @@ fail:
 	*tag_files.tfn = '\0';
 	tag_files.ofd = -1;
 	tag_files.tfd = -1;
+	tag_files.tagname = NULL;
 	return NULL;
 }
 
 /*
  * Set the line number where a term is defined,
- * unless it is already defined at a higher priority.
+ * unless it is already defined at a lower priority.
  */
 void
 tag_put(const char *s, int prio, size_t line)
 {
 	struct tag_entry	*entry;
+	const char		*se;
 	size_t			 len;
 	unsigned int		 slot;
 
-	/* Sanity checks. */
-
 	if (tag_files.tfd <= 0)
 		return;
+
 	if (s[0] == '\\' && (s[1] == '&' || s[1] == 'e'))
 		s += 2;
-	if (*s == '\0' || strchr(s, ' ') != NULL)
+
+	/*
+	 * Skip whitespace and escapes and whatever follows,
+	 * and if there is any, downgrade the priority.
+	 */
+
+	len = strcspn(s, " \t\\");
+	if (len == 0)
 		return;
 
-	slot = ohash_qlookup(&tag_data, s);
+	se = s + len;
+	if (*se != '\0')
+		prio = INT_MAX;
+
+	slot = ohash_qlookupi(&tag_data, s, &se);
 	entry = ohash_find(&tag_data, slot);
 
 	if (entry == NULL) {
 
 		/* Build a new entry. */
 
-		len = strlen(s) + 1;
-		entry = mandoc_malloc(sizeof(*entry) + len);
+		entry = mandoc_malloc(sizeof(*entry) + len + 1);
 		memcpy(entry->s, s, len);
+		entry->s[len] = '\0';
 		entry->lines = NULL;
 		entry->maxlines = entry->nlines = 0;
 		ohash_insert(&tag_data, slot, entry);
 
 	} else {
 
-		/* Handle priority 0 entries. */
+		/*
+		 * Lower priority numbers take precedence,
+		 * but 0 is special.
+		 * A tag with priority 0 is only used
+		 * if the tag occurs exactly once.
+		 */
 
 		if (prio == 0) {
 			if (entry->prio == 0)
@@ -196,16 +227,27 @@ tag_write(void)
 	struct tag_entry	*entry;
 	size_t			 i;
 	unsigned int		 slot;
+	int			 empty;
 
 	if (tag_files.tfd <= 0)
 		return;
-	stream = fdopen(tag_files.tfd, "w");
+	if (tag_files.tagname != NULL && ohash_find(&tag_data,
+            ohash_qlookup(&tag_data, tag_files.tagname)) == NULL) {
+		mandoc_msg(MANDOCERR_TAG, 0, 0, "%s", tag_files.tagname);
+		tag_files.tagname = NULL;
+	}
+	if ((stream = fdopen(tag_files.tfd, "w")) == NULL)
+		mandoc_msg(MANDOCERR_FDOPEN, 0, 0, "%s", strerror(errno));
+	empty = 1;
 	entry = ohash_first(&tag_data, &slot);
 	while (entry != NULL) {
-		if (stream != NULL && entry->prio >= 0)
-			for (i = 0; i < entry->nlines; i++)
+		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]);
+				empty = 0;
+			}
+		}
 		free(entry->lines);
 		free(entry);
 		entry = ohash_next(&tag_data, &slot);
@@ -216,6 +258,10 @@ tag_write(void)
 	else
 		close(tag_files.tfd);
 	tag_files.tfd = -1;
+	if (empty) {
+		unlink(tag_files.tfn);
+		*tag_files.tfn = '\0';
+	}
 }
 
 void