Remove the hack of scrolling forward and backward with +G1G that

many (jmc@, millert@, espie@, deraadt@) considered revolting.
Instead, when using a pager, since we are using a temporary file
for tags anyway, use another temporary file for the formatted
page(s), as suggested by millert@ and similar to what the traditional
BSD man(1) did, except that we use only one single temporary output
file rather than one for each formatted manual page, such that
searching (both with / and :t) works across all the displayed files.

1 files changed, 57 insertions, 20 deletions

diff --git a/tag.c b/tag.c
index 02020663..3b3de023 100644
--- a/tag.c
+++ b/tag.c
@@ -1,4 +1,4 @@
-/*      $Id: tag.c,v 1.5 2015/07/25 14:28:59 schwarze Exp $    */
+/*      $Id: tag.c,v 1.6 2015/07/28 18:38:55 schwarze Exp $    */
 /*
  * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -44,29 +44,49 @@ static	void	 tag_free(void *, void *);
 static	void	*tag_calloc(size_t, size_t, void *);
 
 static struct ohash	 tag_data;
-static char		*tag_fn = NULL;
-static int		 tag_fd = -1;
+static struct tag_files	 tag_files;
 
 
 /*
- * Set up the ohash table to collect output line numbers
- * where various marked-up terms are documented and create
- * the temporary tags file, saving the name for the pager.
+ * Prepare for using a pager.
+ * Not all pagers are capable of using a tag file,
+ * but for simplicity, create it anyway.
  */
-char *
+struct tag_files *
 tag_init(void)
 {
 	struct ohash_info	 tag_info;
+	int			 ofd;
 
-	tag_fn = mandoc_strdup("/tmp/man.XXXXXXXXXX");
+	ofd = -1;
+	tag_files.tfd = -1;
+
+	/* Save the original standard output for use by the pager. */
+
+	if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1)
+		goto fail;
+
+	/* Create both temporary output files. */
+
+	(void)strlcpy(tag_files.ofn, "/tmp/man.XXXXXXXXXX",
+	    sizeof(tag_files.ofn));
+	(void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
+	    sizeof(tag_files.tfn));
 	signal(SIGHUP, tag_signal);
 	signal(SIGINT, tag_signal);
 	signal(SIGTERM, tag_signal);
-	if ((tag_fd = mkstemp(tag_fn)) == -1) {
-		free(tag_fn);
-		tag_fn = NULL;
-		return(NULL);
-	}
+	if ((ofd = mkstemp(tag_files.ofn)) == -1)
+		goto fail;
+	if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1)
+		goto fail;
+	if (dup2(ofd, STDOUT_FILENO) == -1)
+		goto fail;
+	close(ofd);
+
+	/*
+	 * Set up the ohash table to collect output line numbers
+	 * where various marked-up terms are documented.
+	 */
 
 	tag_info.alloc = tag_alloc;
 	tag_info.calloc = tag_calloc;
@@ -74,7 +94,21 @@ tag_init(void)
 	tag_info.key_offset = offsetof(struct tag_entry, s);
 	tag_info.data = NULL;
 	ohash_init(&tag_data, 4, &tag_info);
-	return(tag_fn);
+	return(&tag_files);
+
+fail:
+	tag_unlink();
+	if (ofd != -1)
+		close(ofd);
+	if (tag_files.ofd != -1)
+		close(tag_files.ofd);
+	if (tag_files.tfd != -1)
+		close(tag_files.tfd);
+	*tag_files.ofn = '\0';
+	*tag_files.tfn = '\0';
+	tag_files.ofd = -1;
+	tag_files.tfd = -1;
+	return(NULL);
 }
 
 /*
@@ -88,7 +122,7 @@ tag_put(const char *s, int prio, size_t line)
 	size_t			 len;
 	unsigned int		 slot;
 
-	if (tag_fd == -1)
+	if (tag_files.tfd <= 0)
 		return;
 	slot = ohash_qlookup(&tag_data, s);
 	entry = ohash_find(&tag_data, slot);
@@ -114,13 +148,14 @@ tag_write(void)
 	struct tag_entry	*entry;
 	unsigned int		 slot;
 
-	if (tag_fd == -1)
+	if (tag_files.tfd <= 0)
 		return;
-	stream = fdopen(tag_fd, "w");
+	stream = fdopen(tag_files.tfd, "w");
 	entry = ohash_first(&tag_data, &slot);
 	while (entry != NULL) {
 		if (stream != NULL)
-			fprintf(stream, "%s - %zu\n", entry->s, entry->line);
+			fprintf(stream, "%s %s %zu\n",
+			    entry->s, tag_files.ofn, entry->line);
 		free(entry);
 		entry = ohash_next(&tag_data, &slot);
 	}
@@ -133,8 +168,10 @@ void
 tag_unlink(void)
 {
 
-	if (tag_fn != NULL)
-		unlink(tag_fn);
+	if (*tag_files.ofn != '\0')
+		unlink(tag_files.ofn);
+	if (*tag_files.tfn != '\0')
+		unlink(tag_files.tfn);
 }
 
 static void