Index: trunk/src_plugins/drc_query/drc_lht.c
===================================================================
--- trunk/src_plugins/drc_query/drc_lht.c	(nonexistent)
+++ trunk/src_plugins/drc_query/drc_lht.c	(revision 31491)
@@ -0,0 +1,84 @@
+/*
+ *
+ *                            COPYRIGHT
+ *
+ *  pcb-rnd, interactive printed circuit board design
+ *  (this file is based on PCB, interactive printed circuit board design)
+ *  Copyright (C) 2020 Tibor 'Igor2' Palinkas
+ *  (Supported by NLnet NGI0 PET Fund in 2020)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *  Contact:
+ *    Project page: http://repo.hu/projects/pcb-rnd
+ *    lead developer: http://repo.hu/projects/pcb-rnd/contact.html
+ *    mailing list: pcb-rnd (at) list.repo.hu (send "subscribe")
+ *
+ */
+
+static int drc_query_lht_save_def(rnd_hidlib_t *hl, lht_node_t *ndefs, const char *def_id)
+{
+	lht_node_t *norig;
+	if (pcb_drc_query_def_by_name(def_id, &norig, 0) != 0)
+		return -1;
+	lht_dom_list_append(ndefs, lht_dom_duptree(norig));
+	return 0;
+}
+
+static int drc_query_lht_save_rule(rnd_hidlib_t *hl, const char *fn, const char *rule_id)
+{
+	htsi_t defs;
+	htsi_entry_t *e;
+	fgw_arg_t tmp;
+	lht_doc_t *doc;
+	lht_node_t *ndefs, *nrules, *norig;
+	int res = 0;
+	FILE *f;
+
+	if (pcb_drc_query_get(hl, 1, rule_id, "query", &tmp) != 0)
+		return -1;
+
+	f = rnd_fopen(hl, fn, "w");
+	if (f == NULL)
+		return -1;
+
+	doc = lht_dom_init();
+	doc->root = lht_dom_node_alloc(LHT_LIST, "pcb-rnd-drc-query-v1");
+	ndefs = lht_dom_node_alloc(LHT_LIST, "definitions");
+	nrules = lht_dom_node_alloc(LHT_LIST, "rules");
+	lht_dom_list_append(doc->root, ndefs);
+	lht_dom_list_append(doc->root, nrules);
+
+	htsi_init(&defs, strhash, strkeyeq);
+	pcb_qry_extract_defs(&defs, tmp.val.str);
+	for(e = htsi_first(&defs); e != NULL; e = htsi_next(&defs, e)) {
+		if (drc_query_lht_save_def(hl, ndefs, e->key) != 0)
+			res = -1;
+		free(e->key);
+	}
+	htsi_uninit(&defs);
+
+	if (pcb_drc_query_rule_by_name(rule_id, &norig, 0) == 0) {
+		lht_dom_list_append(nrules, lht_dom_duptree(norig));
+		res = lht_dom_export(doc->root, f, "");
+	}
+	else
+		res = -1;
+
+	fclose(f);
+	lht_dom_uninit(doc);
+
+	return res;
+}
Index: trunk/src_plugins/drc_query/drc_query.c
===================================================================
--- trunk/src_plugins/drc_query/drc_query.c	(revision 31490)
+++ trunk/src_plugins/drc_query/drc_query.c	(revision 31491)
@@ -41,6 +41,7 @@
 #include <librnd/core/conf_hid.h>
 #include <librnd/core/list_conf.h>
 #include <librnd/core/compat_misc.h>
+#include <librnd/core/safe_fs.h>
 
 #include "board.h"
 #include "drc.h"
@@ -648,6 +649,8 @@
 	return 0;
 }
 
+#include "drc_lht.c"
+
 static const rnd_hid_fsd_filter_t *init_flt(const char **fmt)
 {
 	static const char *pat_tdx[] = {"*.tdx", NULL};
@@ -698,6 +701,7 @@
 
 	switch(*fmt) {
 		case 't': case 'T': ires = rnd_actionva(hl, "savetedax", "drc_query", fn, id, NULL); break;
+		case 'l': case 'L': ires = drc_query_lht_save_rule(hl, fn, id); break;
 		default: rnd_message(RND_MSG_ERROR, "Can not save in format '%s'\n", fmt); ires = -1; break;
 	}